fiberglass question

[flight control]

So I've been working on a top secret project with my brother and we've hit a wall. We built a layout mold out of foam because it was free and easy to shape. The plan was to wrap it in plastic and fiberglass over it one half at a time and stick them together. We've done it before on a kayak project, but the mold was wood with a good coat of wax to keep the glass from sticking.

So we finished shaping the foam yesterday and covered it in shrink wrap (it was a thick blue plastic used to wrap and protect boats.) When we started rolling on the resin, the plastic started warping and bubbling. There is no way we can use that stuff.

Does anyone know of a plastic sheet that could stand up to fiberglass resin? We tested that clear vapor barrier used in construction, it might work. Any ideas?

[JGUN]

Wax the plastic and or spray a clearcoat over it first?

[flight control]

That could be an option but I would hate to miss a spot and waste more mat and resin.

I wonder if pallet wrap would work.

A quick google search yielded nothing. I'll keep looking it up when I have more time.

[jehler]

Don't miss a spot

[Bufflehead]

The heat when it starts to cure will probably screw up most thin plastics. Are you using epoxy resin or polyester resin?

[QH's Paw]

First, my disclaimer: "I don't know shit about what ypou are doing".
My first thought would be, why can't you use Teflon based spray on lubricant?

[Feelin' Fowl]

This video uses mylar. Might work for your application...check about 2:55.

[flight control]

The heat when it starts to cure will probably screw up most thin plastics. Are you using epoxy resin or polyester resin?

I hope I can find a plastic that won't react. I'm using polyester resin

First, my disclaimer: "I don't know shit about what ypou are doing".
My first thought would be, why can't you use Teflon based spray on lubricant?

You mean directly on the foam? Its the expanding foam used as insulation in doors. The factory gives away the pieces they cut out for the windows and I'm pretty sure the resin will melt the foam if they come into contact with each other. Also the plastic smooths out any imperfections in the mold. It looked some slick with the tight plastic skin until it got all bubly and wrinkly

[flight control]

This video uses mylar. Might work for your application...check about 2:55.

FF thats exactly the kind of information I'm looking for. He mentions mylar, polypropylene and polyethylene. I'll look those up and see whats available.

Thanks guys!

[assateague]

I believe mylar is sold as window tinting at home depot and the like. Might be cheaper than plastic, if you can find it.

[flight control]

Thanks Assa. I was starting to get discouraged thinking I put in all this work and having it not work at the last step. I know it might still not work out, but I will try everything I can before I give up. Even then as a last resort, I can cover the entire thing in wood strips and wax it to get my layout. We sold our old layout to buy materials to make two of these, so no more layout hunting until I'm successful.

[assateague]

Here you go- 50" x 50 foot roll for $35


http://www.hydrogalaxy.com/growing-lights/reflective-wall-coverings/50-x-50-standard-2mil-mylar/?gclid=CPTz1OOJtbkCFc5FMgodP3YA5g

[flight control]

Holy shit! That looks exactly like the stuff my friend's brother installs on ceilings! It looks kind of funny but I hear it's catching on, he's always busy. The mirror finish is popular for bedroom ceilings

I bet it's mylar and I could get leftovers from him for cheap or free. Now I need to get in touch with him.

[flight control]

Just got back from home depot and I couldn't find mylar, but I did get 6mil polyethylene. Next day I get off, I'll be trying my luck again. But I'll start with a small section and let it cure completely before proceding with the whole project. Fingers crossed.

[Feelin' Fowl]

Good luck!

[flight control]

Ok. I tested a small patch of the polyethylene, same thing. What we did then was wrap the whole thing with pallet wrap, then a good layer of turtle wax. It looks like it worked. It's not perfect, but it will float, and its a huge improvement on our last layout.

IMG740.jpg

IMG744.jpg

[Feelin' Fowl]

Now that you have it formed, you can give it another layer or two of cloth, and resin. It should be more than strong enough after that...

[flight control]

We did three layers. See how that works out. We can always add more later.

[Feelin' Fowl]

We did three layers. See how that works out. We can always add more later.

Should be more than enough. I thought you were just starting the mold...

[assateague]

How you going to get the mold out?

[Feelin' Fowl]

How you going to get the mold out?

Pee on it, of course!

[jarbo03]

How you going to get the mold out?

Pee on it, of course!

Of course, can't believe he even had to ask.

[assateague]

I'm new to fiberglass. Cut me some slack, jack.

[rebelp74]

I'm new to fiberglass. Cut me some slack, jack.

So is your hybrid a hollowed out tree?

[The Duck Hammer]

I'm new to fiberglass. Cut me some slack, jack.

So is your hybrid a hollowed out tree?

I believe he built it out of plywood.


Sent from my Vox Mortem

[Feelin' Fowl]

I'm new to fiberglass. Cut me some slack, jack.

So is your hybrid a hollowed out tree?

I believe he built it out of plywood.


Sent from my Vox Mortem

Not new to fiberglass...

[rebelp74]

Not gonna lie, I could totally see assa using the fire method to hollow out a tree for a boat that would be for everyday use. Don't get me wrong it'd be bad ass but not for everyday use.

[flight control]

that would be badass. Assa, I'm making the top half first, pop it off the mold, then the bottom, pop that off the mold and then taping the halves together.

[assateague]

I figured, but the pics made it look like the glass wrapped around the sides a little way. Must've been tropical.

[flight control]

I figured, but the pics made it look like the glass wrapped around the sides a little way. Must've been tropical.

It does. So will the bottom part. They both get trimmed to say about an inch lip and then one gets stuffed into the other before getting taped together. It's really pretty simple. I love working with fiberglass, except for grinding. That dust is a bitch.