Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam?

Discussion in 'Sculpture and Makeup Effects' started by shareahack, Aug 14, 2017.

  1. shareahack

    shareahack Active Member RPF PREMIUM MEMBER

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    Hi all, I'm thinking about sculpting a full-size t-rex skull out of pink rigid insulating foam (mainly because I was able to acquire a a big pile of old used foam!).

    I'll be doing it in manageable sections and then merging everything together at the end.

    I have some ideas about covering/finishing the foam but am wondering if any seasoned sculptors out there had any good tips. The goal is to cover/paint/seal the foam to the point where it looks and feels like a museum resin fossil casting.

    I really like the darker, more matte weathered look (see attachment):

    [​IMG]

    Ideally the final sculpture will be sturdy enough to stand on and could sit outside and withstand the weather and not easily chip paint (a nice garden centerpiece? :)).

    My first instinct was to coat the foam with PVA or something to protect it from any solvent use. Then I would cover the entire thing with fiberglass/resin, maybe do some finishing work with Bondo etc and then paint, weather, and seal it.

    I'm thinking if I use fiberglass it'll introduce a lot of finishing work because of the grid-like fiber texture so I'm wondering if there's a better alternative - maybe something like Line-X (never used it before)?

    Would your local hardware store automotive Bondo resin be good enough or do you think there's a better alternative? (I'll probably need a lot of this stuff)

    Luckily there's a lot of margin for error on the texturing because of the bumpy/broken surfaces of natural fossils.

    If anyone has any better ideas or time-saving tips I would be eternally grateful. Will be posting progress along the way!

    Cheers
     
    Last edited: Sep 26, 2017
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  2. CT1138

    CT1138 Sr Member

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    That's a cast of "Stan" the T. rex, and one of the best preserved skulls to make reference from. I know a lot of museums use painted foam for their replicas, for example, this Sue head that the Field Museum put out for visitors, which they allowed to be touched. Unfortunately, I'm not sure what kind of foam or paint they used, all I know was that it was extremely sturdy.
    [​IMG]
     
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  3. shareahack

    shareahack Active Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Awesome example of what I'd like to have as a finished product. Great-low-profile mounts they're using in that one. Might just stop by the museum this week and see if someone can give me some tips or get some ideas :)
     
  4. shareahack

    shareahack Active Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    With winter coming up fast I decided to go full steam on the T-rex skull project since most of the work has to be done outside. Here's a quick update on the progress of the skull :)

    Here is the scanned 3D model I'm using of what I believe to be the T-rex "Stan" fossil discovered in Buffalo, South Dakota by Stan Sacrison:

    [​IMG]

    According to the Black Hills Institute, the real-life skull has the dimensions of 58" L x 33" W x 68 1/2" H. (approx. 4.8 feet wide) and I really wanted to make mine match the full scale of the original. Because of this I had to chop the skull model into 8 sections so I could work manageable sections on the CNC router (the router can only work with objects inside of a 2' x 4' work area with a depth of approx 4"):

    [​IMG]

    To make these 3D files workable on the CNC machine, I "sliced" them up into layers to match the depth of the pieces of foam I had (3" inch rigid pink insulation foam).

    For just the TOP LEFT half of the skull, it took about 5 pieces of foam and a ended up creating a jigsaw puzzle of 25 pieces:

    [​IMG]

    Need to run right now but more updates tomorrow :)
     
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  5. clonesix

    clonesix Sr Member

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  6. shareahack

    shareahack Active Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Thanks clonesix looks like exactly what I need. I've already got a bunch of this stuff that I'm going to give a try and see how it holds up with fiberglass:

    FXpoxy-Epoxy Resin 2 Gallon Ultra Clear UV resistant (50-60 sq ft) Countertops, Table Tops, Bartops[/h]
    61KrucyYo%2BL._SL1000_.jpg

    Seems like pretty standard epoxy and just going to mix and smear it on the foam with fiberglass. Was even thinking of using old pink 'hair' fiberglass insulation with the epoxy as the 'skin'. Thinking it might be dangerous to inhale if sanded but might be a cool experiment.
     

    Attached Files:

    Last edited by a moderator: Nov 8, 2018
  7. cavx

    cavx Master Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    I am using a very similar product now. If the parts are greater than 5mm thick, this stuff seems to set up nice and the parts can be quite strong, but if they are thin, they may/will remain flexible for some time.

    The stuff I am using has a potlife of almost an hour, demold time after 24 hours and post cure time of 7+ days if not baked. Bake at 70 degrees C for 3 hours to make it hard.

    Yes you can use this with fibreglass matting (woven or chopped) and it will saturate and set like a rock.
     
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  8. shareahack

    shareahack Active Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    For sure I've got both of the woven/chopped Bondo stuff meant for auto body work. I feel like if I plaster it on the foam it's going to leave behind a grid-like texture that i'll have to spend more time finishing (with either more resin on top or sanding it down etc).

    What do you think about using that pink cotton-candy type fiberglass insulation?

    section-link-insulation-8fd3321e24469b09232b0d46000732e4330ddb48f68e131716cb8054344feac2.jpg

    I mean it's fiberglass...the strands are nice and small, you can use as little or as much as you want, and you can bend/form the strands to the foam surfaces easier.

    I'm wondering if I combine this stuff with resin it would achieve a nice strong shell over the foam that might be easier to control with less artifacts when cured?
     
  9. cavx

    cavx Master Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    I have only ever used this stuff in wall/roof cavities. I see no issue with it as long as you get full saturation of the epoxy.

    Just bought 7.5KG of fast(er) set epoxy so hopefully mix, degas, pour and demold all in a day. Last time I used this stuff, parts were still soft for about 24 hours, but then set rock hard. We are also expecting the temp to reach 37 degrees C today, so really happy that will ensure my parts kick properly.
     
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  10. Lear60man

    Lear60man Master Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Pink foam would be a nightmare to work with. Go to Home Depot and 'borrow' a hand full, then try to get it to lay down smooth with resin.
     
  11. shareahack

    shareahack Active Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    I managed to do some cuts already with the old pieces of foam I picked up...it actually wasn't too bad! MESSY, but workable. Will post some pics later tonight.

    I think that because the foam was aged that it was more brittle/flaky and easier to cut.

    This is the old dirty pile foam I grabbed off a guy from Kijiji:

    [​IMG]
     
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  12. 13doctorwho

    13doctorwho Sr Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    There's a reason fiber glass mat and fiberglass cloth are thin. It would take a lot of resin to soak that pink insulation. I don't think it's as flexible as you think. Generally people do the bulk layers of fiberglass with the cloth (it's thicker and has random threads). Once the desired thickness is reached you put a couple layers of the mat, that's the tightly woven glass. If you want it really smooth when glass layers are cured go over the whole thing with a layer of just resin. With the fibers cured the last layer won't soak into the fibers so it's like painting on a finish coat.
    Just be careful and wear a mask... fiber glass and resin is nasty stuff.
     
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  13. shareahack

    shareahack Active Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    LOL I just realized you meant the cotton candy stuff. Luckily we're in the middle of roofing renos and I've got an abundance of used insulation that's mostly being thrown away because it's all moldy. :thumbsup

    - - - Updated - - -

    Thanks 13doctorwho, good advice. I'll do some tests of all techniques mentioned above. Luckily the texture of the skull is going to be lumpy and imperfect so there's lots of room for error.
     
    Last edited by a moderator: Nov 8, 2018
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  14. Lear60man

    Lear60man Master Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Haha. Yea I was talking about the cotton candy stuff. The stuff in post #11 is perfect for sculpting....mold and all!

    Nice kitty BTW.
     
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  15. shareahack

    shareahack Active Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Here's a photo of the CNC being used to cut out the foam T-rex pieces. Pink snow everywhere!

    [​IMG]

    Each piece of foam is 2' feet x 4' feet. In 3 days of cutting and 5.5 pieces of foam later, I managed to cut out enough pieces to build up just 1/4 of the skull (the top left half):

    [​IMG]

    Lots of fun punching out the pieces from the foam like a giant hobby model kit:

    [​IMG]

    And finally we have something that's starting to look like a T-rex! Still lots of gluing, shaping, and excavating the overhangs to do. I'd say I'm about 20% done:

    [​IMG]
     
  16. kwalsh0000

    kwalsh0000 Sr Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Love the concept man esp the last pic and how it goes together. Great way to merge techniques. Cant wait to see progress.
     
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  17. shareahack

    shareahack Active Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Thanks kwalsh0000!
     
    Last edited by a moderator: Nov 8, 2018
  18. Lear60man

    Lear60man Master Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Man....if you took black an white photos, it would look like the 40's
     
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  19. shareahack

    shareahack Active Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Made a bit more progress on skull. Good news, all the cutting is finished! Just need to manually carve out the overhangs and finishing touching up/sanding (the fun part).

    I used PL construction adhesive to glue the pieces together and then bamboo BBQ skewers to temporarily hold them in place:

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    Started roughing out the top internal geometry of the skull by hand:

    [​IMG]

    A couple bonuses I've learned:

    The teeth overhangs that (stretch across the whole model) are actually useful in protecting the teeth while I work on other parts of the skull. Since they're so skinny they'd be super delicate if they weren't being reinforced by the overhangs. I'll be cutting out the teeth as the last step before fiberglassing.

    The PL construction "300 foam board" glue is actually NOT ideal for foam-on-foam gluing. It doesn't fully cure and leaves the pieces somewhat repositionable...but it does grab well and adequately holds the sculpture in tact...it has the texture/consistency of peanut butter.

    I used the standard PL 3X on the more structural parts of the model and it works great, cures very hard and grabs the foam well.

    The bonus of using the weaker PL 300 for this particular project is it made carving out the internal skull structures way easier when cutting by hand. The PL 3X is very hard to cut through with a knife/saw.

    Happy [Canadian] Thanksgiving!
     
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  20. MooCriket

    MooCriket Master Member

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Looking bad *!
     
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  21. 13doctorwho

    13doctorwho Sr Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    That is so freakin' awesome!!
     
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  22. Ash

    Ash Sr Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Currently WINNING current ongoing project builds right now in my opinion. This is incredibly awesome and something I've wanted to own since I was a little child. You go ahead and let me know when you work out a kit form. :lol

    -Ash
     
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  23. horus

    horus Active Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Is this available for sharing the plans?



    I would only ever have space for a head !
     
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  24. shareahack

    shareahack Active Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam





    Thanks guys! Appreciate the feedback this is the first time I've done a project like this. Totally with you on the childhood dream @Ash :lol

    Spent so much time this week manually carving out the internal structures...skulls are weird shapes and a lot more work than planned getting the details right.

    @Ash / @horus haven't really thought about a kit or what that would entail but interesting idea. When I find some time I'm going to upload all the models and design files I used (for free) if they can help anyone.

    Will also try to make some videos about my workflow/process. Along the way I realized some areas I could have improved and saved myself a bunch of time. If the weather is good will upload some more pics this weekend!
     
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  25. shareahack

    shareahack Active Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Finally finished carving out the internal geometry of the top part of the skull (took way longer than I thought!). Had to cross section the 3D model and really analyze the internal structure to slowly match it to the foam section by section. Used a combination of serrated knives, box cutters, a die grinder (air) with a rasp bit. In this photo the 4.8ft skull is sitting inside the 8'x10' CNC shed (kind of a snug fit in there right now lol):

    shareahack_diy-trex-skull-cnc-foam_3dmodel_14.jpg

    Surprisingly this was by far the most useful tool that I came across by chance. It's a pumpkin scooper that I found at the dollar store. I sharpened the serrated edge using a grinder. Really helped to remove inside material fast in the hard to reach places:

    shareahack_diy-trex-skull-cnc-foam_3dmodel_20.jpg

    Had fun shaping the teeth! The final teeth will have the serrations on the back edges (will add after fiberglassing):

    shareahack_diy-trex-skull-cnc-foam_3dmodel_15.jpg

    shareahack_diy-trex-skull-cnc-foam_3dmodel_16.jpg

    shareahack_diy-trex-skull-cnc-foam_3dmodel_17.jpg

    Apparently T-rex's teeth were the size of bananas. Theory confirmed! :lol

    BBQ skewers added for reinforcement:

    shareahack_diy-trex-skull-cnc-foam_3dmodel_19.jpg

    shareahack_diy-trex-skull-cnc-foam_3dmodel_18.jpg

    Still working on the lower jaw but should be done this week I hope.

    Happy Halloween everyone!
     
  26. Too Much Garlic

    Too Much Garlic Master Member

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    That's a really cool project and coming along nicely.

    Where did you get that 3D file? Looks awesome.
     
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  27. 13doctorwho

    13doctorwho Sr Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    I can not believe how cool this is. I can't wait till it's done!!
     
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  28. CT1138

    CT1138 Sr Member

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Oh man, this is really coming along! It looks great!
     
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  29. daredevil665

    daredevil665 Well-Known Member

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Beautiful and intriguing work!
     
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  30. Leigh

    Leigh Sr Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Awesome!! (y)thumbsup
     
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  31. iloveyouiknow87

    iloveyouiknow87 New Member

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    amazing job man!!!!!!
     
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  32. jess the pirate

    jess the pirate Active Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    You could always coat it with cassini's plaster, or any P.I.P for that matter, that way you could cut out the pva glue stage altogether. It's made for outdoor sculptures and its pretty * cheap. Also whilst its kicking you can add the little details like the stan cast has, i.e pits and whatnot. Just a thought! Keep going, its pretty amazing already and the teeth supports is a genius idea! Well done!
     
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  33. Lear60man

    Lear60man Master Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Ya know......this is the type of thing that you could make a good chunk of change once finished and presented correctly.
     
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  34. ChickenHaunt

    ChickenHaunt Well-Known Member

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Really nice
     
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  35. Barking Dragon

    Barking Dragon Well-Known Member

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Outstanding work mate ;) loving how this is coming together
     
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  36. Howat Props

    Howat Props Active Member

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    wow! this is going to look amazing! I would love to make this myself
     
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  37. shareahack

    shareahack Active Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Thanks all for the feedback! It's been a little bit harder working outside as the weather got cooler but I've made a bit of progress since the last post and have since moved the project indoors.

    Thanks Jess for the great idea to use plaster! I think I'm going to attempt a combination of plaster + cheap clay over the foam on certain areas before applying the resin/fiberglass. I'm hoping the plastered areas dry with cracks (I may try to induce the cracks somehow) to better simulate the look of fragmented bone.

    Here's a few more progress photos of the lower jaw and beginnings of the mounting system. I decided to keep the mounts super simple and easy to disassemble for transporting around.

    I hot-glued some temporary wooden braces/supports to the lower jaw to maintain rigidity while building the mounts. For now, the base is just a piece of MDF with 4 castor wheels on the base. The skull will appear to 'float' over the much smaller base.

    [​IMG]

    Here I cut out a small cavity in the top of skull and epoxied in a piece of plywood with a cast iron * screwed on to it. I slathered epoxy and polyurethane glue so that the glue would puff up and expand into he foam cavities. Once In place I jammed a bunch of the bamboo BBQ skewers in and around the wood to reinforce and spread the tension over a wider area. I then added more poly glue to firm everything up. A 1/2" black iron plumbing pipe will do most of the work holding up the skull. This main connection point will be reinforced later with fiberglass mat and resin.

    [​IMG]

    I hoisted the top part of the skull up with a rope to more easily balance it in position over the base:

    [​IMG]

    I used another scrap piece of pipe and a decorative */cover thing I found to act as the base's pipe holder that mates with the iron pipe:

    [​IMG]

    To hold up the lower jaw, I machined these little side-mounted connectors that are fastened to the sides of the jaw in 4 places. I mounted them on plywood so they have a firm base to hang on to instead of just the foam. Later on these connection points will also be reinforced with resin/fiberglass. The chicken wire was just an afterthought and I figured it might help with grabbing on to the fiberglass/foam.

    Smaller steel dowels run through the pipes that will connect to t he side mounts. The mounts have set screws tapped into them to hang on to the dowels when in place.

    [​IMG]

    And here's a look at what the final orientation/positioning will be! I can modify the height, position of the jaw, and how open the mouth is just by changing the lengths of the iron pipes.

    [​IMG]

    Every now and then I post some progress/videos on Instagram if anyone interested: https://www.instagram.com/shareahack/

    Hope everyone is gearing up for a great holiday! Cheers
     
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  38. 13doctorwho

    13doctorwho Sr Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    God, I love this project. I am super jealous!
     
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  39. CT1138

    CT1138 Sr Member

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    It's really taking shape into something gorgeous!
     
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  40. daredevil665

    daredevil665 Well-Known Member

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    Compelling work! I like solutions. I am eager to see more progress!:thumbsup
     
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  41. Barking Dragon

    Barking Dragon Well-Known Member

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    It's really coming along now, great progress pictures as well :)
     
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  42. shareahack

    shareahack Active Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Happy Jurassic June!


    Sorry for the delay in posting...it took a few weeks (off and on) but I'm happy to say the fiberglassing is finally DONE!


    I waited out the winter and moved the project outside into a car shelter to avoid any possible VOC problems from the epoxy and dust particles from the fiberglass.


    I decided not to mess with any polyester resin (yet) due to the risk of melting the foam. I used almost 3 gallons of epoxy to cover the entire surface area of the skull.


    I ran out of the original 2 gallons of counter top resin I had so I decided to buy smaller batches as I needed it to finish the fiberglassing.


    The second type of epoxy I tried was West System (way more expensive but clearly superior than the counter top stuff...cures extremely hard and more sandable).


    When I ran out of West System, I tried some cheaper "Envirotex" brand that I found at Michael's (the 50% off coupons didn't hurt!). To compare, 1L of West System was around $80 (with hardener) and the Michael's stuff was around $30 for the same volume. The cheaper brand cures slightly more "rubbery"/flexible but it was perfectly adequate for finishing off this stage of the project.

    [​IMG]

    I used a combination of fiberglass mat and woven cloth. Lost track of how many sheets I bought but it was quite a few (maybe around 10 sheets of 8 sq feet - so around 80 sq feet was needed to coat the whole skull.

    [​IMG]

    I started with the hardest part (the teeth) and laid down the glass strips in a combination of ways (lengthwise, spiraled around the tooth, etc).

    [​IMG]

    I removed the wooden supports from the lower jaw and drilled/tapped a couple of metal corner brackets to act as a linkage to connect the left and right lower jaw pieces with a single screw.

    [​IMG]

    Before fiberglassing the rest of the skull I started with reinforcing all the metal mounting points and linkages.

    [​IMG]

    The mat was more epoxy-hungry than the cloth and it took a lot to saturate it but it was perfect for molding around awkward shapes and crevasses. The woven cloth helped to bridge the mat and add good structural reinforcement.

    [​IMG]

    Sometimes the fiberglass wouldn't 'stay down' very well especially when it was hotter outside. My solution was to lay down the glass in position as best I could, wait a couple hours for a bit of curing to take place and then push down the parts that were springing up into the foam - this worked out well because after a few hours the resin has more of a putty consistency.


    A cool little tip I found out: After laying down a strip of glass, the little left-over strands/resin on your gloves - you can work them into a little ball and use it like a putty/filler to cover up an exposed area or hard to reach place.

    [​IMG]

    Finally everything is coated and extremely durable...I'm hoping it will last forever! Next I need to clean up all the sharp fiberglass spillovers and knife-like edges.

    [​IMG]

    A full timelapse of the fiberglassing (condensed to 1 minute) can be watched here:


    https://www.instagram.com/p/BkcQ5EwhpR4/?taken-by=shareahack


    Thanks for reading!
     
    Leigh likes this.
  43. Too Much Garlic

    Too Much Garlic Master Member

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Looking awesome. Looks big and menacing. :)
     
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  44. tarnyloo73

    tarnyloo73 Active Member

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Great project and looking good. Must make one for myself one day.
     
    shareahack likes this.
  45. Lunajammer

    Lunajammer Active Member

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    I admire your knowledge and mastery of the materials. Your commitment to the project is also admirable and the results are fantastic. Really looking forward to seeing where this ends up. Nice work and thanks for sharing your techniques.
     
    shareahack likes this.
  46. shareahack

    shareahack Active Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Decided to spend some time reinforcing the teeth... I figure the teeth will be the first thing my nephews want to run up and grab. The fiberglass has made them pretty strong as-is but I want to make sure they can withstand the full force of a group of 5 year olds :)

    I found a bunch of scrap threaded rods, screws and metal dowels:

    [​IMG]

    I measured/cut the rods to length and sharpened them all to a point:

    [​IMG]

    For the threaded rods, I made little slots to be able to use a screwdriver to drill the rods down below the teeth tips:

    [​IMG]

    Now time for the root canals...I drilled holes in all of the teeth to get the metal rods seated:

    [​IMG]

    Drilled the rods deep into the skull, passed the "root" of the teeth into the skull. For the small teeth I just used regular long construction screws:

    [​IMG]

    Quick video of the process here: https://www.instagram.com/p/Bkx5UhihTPr/?taken-by=shareahack

    Next I'll be shaping the tips of the teeth with bondo and probably covering them in more resin/fiberglass.

    Time to stop procrastinating and start cleaning up / sanding the fiberglass (I've been dreading this part!).

    Cheers
     
    Leigh likes this.
  47. animator

    animator Active Member

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    This is just the best project ever!

    I showed this thread to my son who loves dinos and he said, "Daddy, you couldn't do that." ...reality is harsh
     
  48. shareahack

    shareahack Active Member RPF PREMIUM MEMBER

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Thanks animator! Honestly this is the first project I've ever done like this (my first time using resin/fiberglass too). Somehow got the idea and just had to pursue it as I'm sure everyone here can relate :) Jury's still out on what the final product will look like lol :)
     
    Last edited by a moderator: Nov 8, 2018
    cckaiser2 likes this.
  49. tarnyloo73

    tarnyloo73 Active Member

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Good call making the teeth nephew proof. Kids are masters of incidental demolition :)
     
    shareahack likes this.
  50. animator

    animator Active Member

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    Re: Full Sized T-Rex Dinosaur Skull - advice on coating/finishing/painting rigid foam

    Any updates? I can't wait to see more!
     

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