fiberglass resin question

[filske]

*Sorry in advance if I post this the wrong place*

I'm new to this resin stuff and I really want to make sure I don't 5L of the wrong stuff before I start resin my costume.


Scenario:

• I need to resin the stuff in my livingroom (that's right my livingroom).
• I have a respirator mask, but the stuff still needs to dry in my livingroom/and or my balcony.
• I need to coat the inside with fiberglass.
• I want to coat the outside with body filler.
• I would like to use a heatgun to manipulate the pieces in the end so whatever I use, needs to soften a bit by heat.

ATM I've found a supplier that offers both Epoxy and Polyester, however I'm having a hard time figuring out which one to chose from or what to look for, given my aforementioned scenario.

Epoxy:
http://www.ekomposit.dk/epoxy.html

Polyester:
http://www.ekomposit.dk/polyester.html

Any ideas will be greatly appreciated

 

[Teddz]

If you're going to do this in your living room, go with the Epoxy. Polyester resin has a really strong smell that will stink up your entire apartment, take a few days to dissipate and could also upset your neighbors, whereas Epoxy doesn't.

 

[filske]

So what's the difference between epoxy and polyester, besides the smell in this case?

Because the guy I talked to said that Epoxy wouldn't soften by the heat gun, actually it would only harden faster... so that's why I'm a bit reluctant to use Epoxy

 

[IEDBOUNTYHUNTER]

First off. You shouldnt do anything in the house. Epoxy may not smell as bad. But its still toxic.

As for whats better. Epoxy is the best. Almost zero shrinkage and alot stronger than fiberglass. The trick to doing any resin work is. Try to get the parts as dry as possible. Meaning the less resin the better. Less resin stronger part.

But seriously. Try to do it outside. Its messy. Stinks and gets everywhere. And like i said its Toxic.

 

[Teddz]

Don't worry yourself too much about fixing sags. If you did things right, there should be very little sag to fix. The body filler stage will take care of the lower spots (sags) anyway. Honestly, unless you used a light-weight paper, you'll be fine with wetting out the card stock. You may also want (depending on what you're building) to install some temporary bracing in areas that may sag. What you're looking for is large, flat areas. These will need something behind them for support or when you wet out, make sure the area is in a position so that gravity doesn't do it's thing like upright. The key here is getting it reinforced correctly so as to cut down the amount of low spots.

I used polyester resin (didn't have epoxy) on my episode 7 Stormtrooper helmet pep and even though the pep was pretty much on point and symmetrical, once the polyester resin cured after the fiberglassing stage, I noticed some sags and distortions. Nothing major, but enough to see that I should have gone with epoxy.

Check out this Youtube vid that should clear it up for you.

 

[filske]

Teddz you're a lifesaver!

 

[Duncanator]

You can reshape epoxy with heat after it has set. I haven't tried that on polyester.

I can't stand polyester. It's cheaper and does a fine job, but Lordy it stinks!

 

[Bigturc]

You can reshape epoxy with heat after it has set. I haven't tried that on polyester.

I can't stand polyester. It's cheaper and does a fine job, but Lordy it stinks!

I have to agree with Don, go epoxy all the way, you won't regret it!


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[Ruddigger]

Have fun wearing a respirator around the house for a couple days.

 

[filske]

So I went with epoxy and fiberglass.

I failed to neglect the importance of bracing. I did some but clearly not enough because the shape isn't perfect. Furthermore some of the smaller flaps buckled under the stress of the weight from the fiberglass.



Now my big concern is that it's all wasted.Are these details fixable?
I was considering buying a heatgun, but seeing as the Epoxy needs heat to harden, I'm having a hard time understanding how heat, again, can make it soft and manageable.

Another worry I have is that my bodyfiller won't stick to my very solid but slippery surface of Epoxy.

- any insights to these issues will be much appreciated

 

[Leigh]

Key the surface with 40 grit paper, should give your body filler plenty to stick to. Now you have a rigid structure you can cut & reposition parts of it using fibreglass or FG paste to bond parts back together. You could also use FG paste & filler to alter areas that need minor adjustment to get the shape your happy with. If your needing to build up an area to quite a thickness bulk it up with FG paste & then (If you need to) you can grind out the inside to remove the unwanted extra material.

HTH

 

[Teddz]

Did you epoxy the pep outside first, let it set, then go with epoxy/fiberglass on the inside or did you just do the epoxy/fiberglass right away? How heavy of a card stock did you use?

Unless the pep is really, really bad, it's salvageable. Although the amount of work involved now will be much higher. Get the heat gun and try to massage it back into shape. You'll need a heat gun anyway, so might as well get one.

As for the "slick" surface, you should use some sandpaper to rough it up a bit and knock down some of the high-spots anyway, but even if you don't get all of the "slick" taken off, don't worry, the filler will stick to it. You want a surface clear of dust & oils or the filler will come off. Be careful with 40 grit as it cuts material pretty fast and it's very easy to poke through the surface.

 

[Bigturc]

First you pep with card stock, then epoxy on the outside. Let dry. Then epoxy with fibreglass on the inside. Let dry.

It should never warp if you follow this procedure!

Putty will definitely stick to it.


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[filske]

Did you epoxy the pep outside first, let it set, then go with epoxy/fiberglass on the inside or did you just do the epoxy/fiberglass right away? How heavy of a card stock did you use?

Unless the pep is really, really bad, it's salvageable. Although the amount of work involved now will be much higher. Get the heat gun and try to massage it back into shape. You'll need a heat gun anyway, so might as well get one.

As for the "slick" surface, you should use some sandpaper to rough it up a bit and knock down some of the high-spots anyway, but even if you don't get all of the "slick" taken off, don't worry, the filler will stick to it. You want a surface clear of dust & oils or the filler will come off. Be careful with 40 grit as it cuts material pretty fast and it's very easy to poke through the surface.

I did 3 layers of epoxy on the outside, let it set for a few days, then moved on the epoxy + fiberglass mat on the inside. and I used paper stock 200g/m2.
I dunno it just seems like some of the hotglue got undone in the process + my bracing wasn't perfect. But I guess it's a matter of definition of bad pep I think it looks alright, It just have some dents here and there and a very noticeable non-alignment on the shoulders and ribs area, as my pictures can tell.

Are there any limits to what the heat gun can do? like... is there a point to where a heatgun can't fix it? like if the pep is too out of ideal shape, or if I used 3 layers of fiberglass for instance..

Atleast now I'm not worried about the bodyfiller part

Once again I highly appreciate you guys taking the time out to guide me through

 

[STEALTH]

always need to remember to use braces everywhere when you're doing large pieces. Even make your own out of cardboard to the size you need and hot glue them in between where you need to line it up properly. going forward with this might be a lot of work in the end to fix versus making a better version of it again.

I would take this a lesson learned and start over in my opinion man,.

 

[Bigturc]

What stealth said ^^^. That's how pep works .. one to learn, one to get better, one to rescale and perhaps another one after that.

Think of the time you'll take to warm it up, try to reshape, try to hold that shape with bracers, it will warp back, frustration, do it again, still warp anyway. Restart.

See right there. Go directly to restart. Keep your first one and compare with the new one, each new iteration will make you laugh of the previous one!

 

[STEALTH]

What stealth said ^^^. That's how pep works .. one to learn, one to get better, one to rescale and perhaps another one after that.

Think of the time you'll take to warm it up, try to reshape, try to hold that shape with bracers, it will warp back, frustration, do it again, still warp anyway. Restart.

See right there. Go directly to restart. Keep your first one and compare with the new one, each new iteration will make you laugh of the previous one!

So right ^
You'll feel so much better starting fresh. you will notice how you have already grown from the first attempt

 

[filske]

*update*

So I've gone against some peoples advice here, and tried to shape things back again with a heatgun - It worked and I now have my pieces all fitting, all lining up to one another beautifully

However I've begun the whole sanding phase, and I'm curious to know when it's enough? I've started using some fiberglass bondo(for the sake of strenght) but I've soon come to realise that it also seems it leaves some ugly strands and pits in the outcome, that is just a pain.(see image)

(look at those craters... 1milimeter deep, but nasty as hell)

Basically I have some voids, I have some ugly looking craters and I have some endings that is not good enough yet.

- I have a feeling throwing a more refined bondo layer ontop will do the job, but I would love to hear what you guys think?

 

[Halex]

The question of "when is it enough" is one of the best and worst questions about this hobby... it's all subjective. It's done when you're happy with it, and not a moment before. The structural bondo with embedded fiberglass is great for added strength on the inside (fiberglass cloth/mat is hard to get into some areas), but in my experience it's best to stick with regular bondo on the outside.

Take as much time as you want with each piece, and only move on once you're satisfied. Add little bits of bondo at a time, doing your best to keep it consistent with the overall shape of the pep piece underneath. Use high grit sandpaper or a rasp on the early layers, moving onto finer and finer as the shape becomes more refined. Remember the bondo's only there to enhance/smooth the shape, not to form it; that's what the pep does. Use it as sparingly as possible and you'll generally have better results.

One more thing... don't be afraid to sand through the outer paper layer in some spots to round off points in the pep model. This is very common and helps save a lot of bondo and weight in the long run.

 

[filske]

*update*

So things are progressing and I'm getting some real nice stuff I can show you guys

Shoulders:


Chest & back:


So it's progressing. Got both arms resined and will soon start to mount them - however I still need to find a good way of doing that, while still keeping some level of movability.


But I've run into a problem, I accidently pushed through a corner on the chest with the sandblaster, and now I'm not quite sure what to do, as it hasn't punctured through the fiberglass underneath it.

The issue:
1cm2 breach


Any input on solving that in a good way will be much appreciated - personally i'm thinking of just giving it a blast of Epoxy, but I could think of a few things that could go wrong with that.