What is wrong with my Vaccuform setup?

[Fett80]

I have recently decided to try my hand at vaccuforming. I am vaccuforming with a shopvac of 5 HP and the thickness of the styrene I use is .06 '' I set my oven at 300 F and let the styrene bake for 2m30s. When I get the styrene out of the oven I quickly put it down on my model and start the vaccum.

I have joined one picture of my vaccuform table and the other picture show that my vaccuform mask as a lot less detail that the one I have rotocast.

It seems to me that my shopvac is not strong enough. I know that I can get a 6.5hp will it make a big difference or should I look elsewhere?

I dont want to use tiner plastic because the mask will be to weak.

By the way, the teeths are cast seperately :lol

Any help would be apreciated

 

[Judge Spartan]

I use a stronger shopvac with my vacuformer and even use .080 polystyrene but you will always have less detail while vacuforming. It is best to use this method with objects with less detail.. Best of luck

 

[jolive]

Has anybody used kydex for vac forming? I'm bout to try...kinda feel like i should've bought .06 instead of .08

 

[Judge Spartan]

Make sure you dry it for about an hour before you use it. All you have to do is place it in the oven at about 200 degrees for about an hour, then let it cool down to the point you can handle it, frame it up , heat it like normal and run it as always. It will not sag as much as polystyrene so you'll have to touch it when it sags, if it is pliable enough you're ready to go. Good luck
BTW, if you don't dry it, it retains moisture and may bubble while heating it up at high temp to use.

 

[shrekkiller]

I read on the dented helmet that you are better of using a house vac b/c it has more pressure from the start. Apparently a shop vac can pick up bigger items b/c of it's hp but a house vac creates more suction when it is first turned on

 

[LORDXBLACKWOOD]

Most of the time when pulling something with that much detail you'll need to drill some small holes in the recesses of the larger areas. In this case it would be between where the teeth are placed.

 

[jolive]

@ judge Spartan... Do you think .08 kydex would be suitable for vac forming? i would hate to waist any.

 

[Judge Spartan]

@ judge Spartan... Do you think .08 kydex would be suitable for vac forming? i would hate to waist any.

Yes you can use it, just take your time. I prefer .080 and wish I still had some of the things I've done I could have linked some pics but that was before I got into costuming. Just remember, the thicker the product less detail..

 

[Spydwar]

Most of the time when pulling something with that much detail you'll need to drill some small holes in the recesses of the larger areas. In this case it would be between where the teeth are placed.

I think you nailed it. I use a motor that will pop 0.1 abs and still get bad pulls when I dont ad holes to allow the motor to draw air from high detail areas. I also usually hollow out the bottom so that the small draw holes have direct access to to the table holes this usually works pretty well.

 

[Judge Spartan]

I think you nailed it. I use a motor that will pop 0.1 abs and still get bad pulls when I dont ad holes to allow the motor to draw air from high detail areas. I also usually hollow out the bottom so that the small draw holes have direct access to to the table holes this usually works pretty well.

Make sure the holes you drill aren't too large or they leave dimples in the final part. If you have a hard time separating your part from the buck use a compressor and blast a burst of air between the buck and plastic and it should pop out quite easily..

 

[Spydwar]

Make sure the holes you drill aren't too large or they leave dimples in the final part. If you have a hard time separating your part from the buck use a compressor and blast a burst of air between the buck and plastic and it should pop out quite easily..

Agree totally I usually just use a 1/16 to 1/8 and if I need to get a better evacuation just add a couple more holes.

 

[tictoc]

That looks pretty good.

I would concur about the vacuum holes between the teeth and the nostrils. You can make a small drill bit holes by using wire (like from a coat hanger). Pound the end flat and sharpen.

Also, make sure your plastic is dry and your buck is warm. Styrene doesn't really absorb moisture but I find I have much better results when I "dry" the plastic at a low temp before forming. Maybe it's just getting uniformly warm throughout...?

A cold buck will start to cool your plastic prematurely. I place mine in my oven prior to forming and use a heat gun to help problem areas.

Let's see if you have any better success. That skull looks awesome!

EDIT: Don't forget to allow the styrene to sag a bit more due to the height of your buck. That is trial and error too.

 

[Gordon Gekko]

I would guess that if you're using those little paper clamps to hold the styrene between your frames, you are losing some suction when you press down. I generally use two 3/4" thick MDF frames that are screwed together in several places.

It doesn't take much to lose enough suction to cause the problems you are having.

 

[Fett80]

Thanks for the tips guys! I have already drilled holes between the teeths it dosent show well on the picture. I will try to heat up the model a little bit.

I may have to swap shop vac, do you know witch shop vac is the strongest for vaccuforming?

thanks

 

[Fett80]

I would guess that if you're using those little paper clamps to hold the styrene between your frames, you are losing some suction when you press down. I generally use two 3/4" thick MDF frames that are screwed together in several places.

It doesn't take much to lose enough suction to cause the problems you are having.

That could be right. I will look into it.

 

[tictoc]

Boy, a 5 hp is pretty good. Mine is a 2.5. If you can't get better results by the above heating, other etc. suggestions...I think you need a second stage vacuum source.

 

[Ray48]

I know a guy that uses two 6hp shop vacs to improve results. Better is to buy a vac pump on line or a manual hand pump is available at many auto parts stores. You will need a one way sump pump type valve from a hardware store. That prevents air from competing with the flow to the shop vac. Install it on the platen side of the valve and switch off the vac after it has pulled to max depth and finish with the hand pump. Other options are a more expensive electric vac pump and there are ways to rig an air tank so you have the air pre-evaccuated so it will suck air in when you open a valve.Any bicycle pump also can be made to work; just plumb the former to the inlet instead of outlet ...that is the only difference for a vac versus a regular air pump...direction of air flow. having said that ,everyone elses comments still are valid. If you want to use thinner plastic you can reinforce the reverse side after pulling with glass but not practical for production runs...you didn't say if it is "one-off" or not.GOOD LUCK!

 

[Judge Spartan]

I use a 6.5 hp shopvac and turn it on just before I drop the styrene down over the buck and get really good results.