Fiberglassing Q&A (mostly q's hoping for a's)

[hydin]

I am about to take my first trip into the realm of fiberglassing, and I want to make sure I don't screw it up.

I know there are people on the board who are incredibly talented with this sort of material, and I hope they chime in with some advice.

My main thing I am doing is repairing a mannequin with a cracked back/side area. I understand how to repair it, and I understand what to get TO repair it, but what I fear is not sealing off the fiberglass and causing problems to the costume the mannequin is for.

Is there anything I can buy off the shelf that is a good "sealer" that won't affect cloth? I know if you don't get the glassing just right, it can stay tacky for years to come, and I really don't want to mess up any costume I use for display on this guy. I thought some spray acrylic sealer (i.e. what you use on paintings), but wasn't sure if that would be a bad idea or not.

Also, any worries on painting it after it's dry? I mostly worry about something acting as a solvent after I already glassed up what I needed finished, and destroying the work I have already done.

Thanks in advance guys.

 

[clonesix]

Glassing a mannequin? From the inside or the outside?

I don't think that cured resin will effect a costume. Just be sure to give it a good wet sanding so as to avoid snags on fabric.

 

[Raffles]

Skin over the cured FG with bondo or car body filler to make sure it's glass smooth.

 

[hydin]

I am glassing the outside of the mannequin to make sure the cracks stop where they are. I don't have a mannequin mold (although, it would be pretty cool to make these guys).

I didn't think about the bondo... I was planning to wet sand it to get it nice and glossy, but I bet adding the bondo to it would make sure that it doesn't end up leaking some kinda chemical goo onto the suit I want to put on it.

Appreciate the advice so far guys! Keep it comin!

 

[weaselflinger]

I've never heard of polyester resin staying tacky unless it's being cast in a silicone mold (in which case, rub it down with acetone and a paper towel and it will be fine) or sometimes when it is mixed with bondo, people forget to add both activators to the mix.

If for any reason it remains tacky after a few hours, you could dip a brush into the activator and brush more onto the surface and that will cure any stickyness.

 

[yakcam]

I've been asked questions about tacky resin, only to find that the resin to catalyst ratio was extremely wrong like 10-20% of what should have been used. It's very hard to screw up the resin mix, as with the above, it was a misreading of the recommended mix ratio. Even if your short by, say, 10% of catalyst, it will still dry in a reasonable time frame.

I suppose there is a chance of getting a "bad batch" of resin, but that would be extremely bad luck and rare.

I know I'm repeating the above, but then all you need to do is wet sand, bondo, sand, prime and paint and voilà. You shouldn't get any kind of seepage , the only thing I can think of would be the smell of the paint might get into the costume, so just let it air out for a while.

I hope this helped in some way

Cheers,

Kraig

 

[exoray]

I've never heard of polyester resin staying tacky unless it's being cast in a silicone mold (in which case, rub it down with acetone and a paper towel and it will be fine) or sometimes when it is mixed with bondo, people forget to add both activators to the mix.

Unwaxed polyester resin will develop a tacky surface... But almost all over the counter polyester layout resins contain wax now unless you request it without...