resin questions? casting ? finishing?

[imported_DANA1]

i have been using usc polyester #58020 wich I understand has wax in it I think? It worked well for the smaller jobs done all in one application. big project can not be done in one mix I'v got all my peices "bulkhead floor etc" cut and ready. I decide to coat everything in resin thinned with a little acetone, to get all nooks and spaces water tite "would be hard to do during final install" here is my problem. should i scuff all parts to be bonded and wipe with acetone or just wipe with acetone or just assemble and glass? thanks again.

 

[Saskatoon2005]

Re: resin questions? casting ? finishing?

Lightly sand to remove that wax, or delamination could occur. Do it right the first time and then forget about it. Then wipe with acetone, then reglass. Good Luck!

Patrick

 

[imported_DANA1]

Re: resin questions? casting ? finishing?

hey Saskatoon is what i did o.k. or should I have done something different? should i have used a resin without wax if i now im going to be glassing over it?

 

[klos]

Re: resin questions? casting ? finishing?

The only reason for the wax is to get a tack-free finish. If you let the resin cure and the wax surface then you will have to gring off the wax to get a good mechanical bond for the next layer. Acetone alone will not remove the wax.

I would use resin without surfacing agent (wax). You can aways add it if you need a tack-free finish.

 

[OhioLowell]

Re: resin questions? casting ? finishing?

I was looking at a can of "bondo" fiberglass resin in the auto parts store yesterday. How do you know if it has the surfacing agent in it or not? Would it be listed somewhere?

If you were to do your layups before the resin kicks all the way would you have to do all the grinding? What I mean is allow one coat to start to gel then apply the nex etc.etc?

Thanks,
Lowell

 

[iwombat]

Re: resin questions? casting ? finishing?

If it's not "Laminating Resin", or it doesn't say "Wax-Free" then it's got surfacing agent in it.

 

[ondarvr]

Re: resin questions? casting ? finishing?

If you start the next layup before the first one is tack free, then you will get a good bond even with a waxed resin.

 

[klos]

Re: resin questions? casting ? finishing?

Exactly what ondarvr said.
Do not allow to completely cure before next layup. Also a chemical bond is much better than a mechanical bond.

 

[imported_DANA1]

Re: resin questions? casting ? finishing?

could you please explain mech bond vs chemical bond?

 

[ondarvr]

Re: resin questions? casting ? finishing?

A chemical bond is when the first layup has not cured completely, the second layup will then crosslink very well with it, it's almost like one layup. A mechanical bond is when the first layup has cured completely and you have sanded the surface to achieve the bond. There will be some crosslinking, but not much, the bond is from the rough surface and the small strands of glass that have been exposed and sticking up. A chemical bond is better, but a mechanical bond can be very good also.