[Danbuc]

Too god damn lazy to search, somebody tell me stuff so I can throw more money at my bike and finish the tail.




I'm planning on going the 'lay glass directly on foam/melt foam/re-enforce with more glass internally' method there.


Using the pink (same as blue) Polystyrene insulation foam to build the tail. I cannot for the life of me remember which resin type is foam safe and does not eat through the foam. Is it epoxy?


I have the shape I want just need to order up some shit. Also, where you guys buying from? I've heard great things from West System resins, any other thoughts though?


Thanks erbody.

 

[MikeGyver]

Epoxy should be fine. West Systems is good. Sometimes you can find it at marine/boat shops to avoid shipping costs.

I use the stuff from this seller http://www.ebay.com/sch/polymerproducts/m.html?_nkw=&_armrs=1&_ipg=&_from=

 

[Danbuc]

Sweet, actually have some leftover epoxy resin from two years ago but that stuff is probably trash now. There's a boat sales/maintenance shop down the highway from me. I'll give them a ring tomorrow and see what the deal is.


Edit: checked out that eBay seller, prices seem pretty good too.

 

[Danbuc]

Sweet, looks like the boat place right down the street sells West Systems stuff. Guess I'll swing by there this weekend and pick some up. Will try out some of my old epoxy shit though to make sure it's safe on the foam first.

 

[guy]

I wouldn't be surprised if the old epoxy doesn't harden at all. The shelf life is not all that long.
The foam will be fine, I always paint the foam mold with latex house paint after I get the shape right, it will hold its shape and not distort during vacuum or heat-curing. The foam may not distort, but the epoxy will need to reach 120 f to cure properly.
One thing with the epoxy, is that it comes in different viscosities and you use the thinnest, or "lay-up" resin to make the parts. also, epoxy doesn't break down the stuff that holds together the fiberglass matting together very well ,this makes it harder for it to lay down flat around the edges and let out air bubbles. This is why I always vaccum parts like this.

 

[Danbuc]

Hmmm good to know. I think the West 105 stuff is supposed to be good for basic wet layup kind of deals. I've seen the basic glass right on foam gig done before so I know it works. Just takes a lot of sanding and filling to get smooth but oh well. I do not have a vacuum bag set up to work with and some portions of the tail are simply too thin to withstand that much force.

I guess I should find a thinner glass matting that's more pliable to use so I can mold it around all the curves. Worst case I get some hard edges, that's what the DA and body filler are for.

As long as the foam will hold its shape fine being in direct contact with the curing resin I should be fine. The foam I'm using is very very dense and not very porous at all like that floral foam so it should hold up well I think.

Guess I'll find out soon enough lol.


Is there a particular filler that would be better suited to this sort of thing? I imagine something flexible like what you would use to fill in damage on a plastic car bumper would be better than say standard bondo?

 

[guy]

I would make my own filler with chopped up bits of glass and the epoxy. Jb weld works good too.
The best thing about epoxy is, you can control how much time it takes for it to start to harden. If you work with it, at room temp, you have as much as 45 minutes to get it all worked out, as soon as you introduce heat to it (90-120 F) it will begin to cure at a speed proportional to the temp.

 

[Danbuc]

Hmmm job weld and left over glass you say. Can that be sanded smooth enough for paint? I would have figured a flexible body filler would have been easier to work with.


I'll be working in a 65° garage so I should have a decent amount of time to mess with it I think.

 

[Mista M]

For non structural construction like you are doing. West System is overkill. They are a great company, for any info regarding layup. Consult there website, too much bad info on the net.
I use http://www.uscomposites.com/ for my non structural projects. When im building or repairing boats, nothing else but West system.

Personally, I would use the epoxy you have. Assuming it was sealed and left in moderate temps out of the sun, its fine. Been there, done that.
Epoxy kick (working) time is determined by the hardener. There are slow and fast hardeners. Vary's by brand, but generally, slow and fast. Keep it on ice to slow the kick down.
If mat is what you have, then yes, it will be a chore to get it to lay down right. Use the wet method, and wet the mat out before putting it on. Put relief cuts in it before hand to make it go around curves.
For filler, jbweld may work, but thats making more work than necessary imho. Ghetto micro fillers:Mix up a dixie cup with some epoxy and some flour or corn starch.
Or buy the micro fillers at your local place. Some local places sell there own brand of epoxy or the west system knockoff.

 

[Danbuc]

I ordered a quart of 105 and a pint of 205 with the pumps and some of the high density filler to try out. I'll see how it goes picking it up Tuesday after work.

All that was a hundred bucks. Probably a bit much but whatever. If I need more I'll just get cheaper stuff lol.

As for the old resin and hardener, its been on the shelf in the garage for two years but......It has been pretty damn cold in there. Heat wasn't much of an issue though. I guess I could try a test batch and see.

 

[Handsome Matt]

We prepped our molds (made from the same pink foam) for the TT Bike with high gloss latex enamel paint at the suggestion of the formula SAE team. It protects the foam from the resin and gives a decent finish for your surface.

 

[Danbuc]

Like just regular latex house paint? I've got some of that laying around I can try. So does the latex paint just end up as sort of a reverse gel coat on the inside? Did you just continue to layer up the glass on the outside, or did you just layer more inside right over the paint?

The foam and seat pan are one piece on this tail, and not just a plug. The seat pan is structural and will have to be molded to the everything else. Shape wise I kind of wanted to leave one solid layer on top, and everything else underneath but if the underside is coated in latex will that work?

 

[Handsome Matt]

Like just regular latex house paint? I've got some of that laying around I can try. So does the latex paint just end up as sort of a reverse gel coat on the inside? Did you just continue to layer up the glass on the outside, or did you just layer more inside right over the paint?

The foam and seat pan are one piece on this tail, and not just a plug. The seat pan is structural and will have to be molded to the everything else. Shape wise I kind of wanted to leave one solid layer on top, and everything else underneath but if the underside is coated in latex will that work?

Just regular latex house paint. It's not a gel coat, just a way to prep the mold so it will prevent the fiberglass from eating the foam and make removing the part easier. We painted a few coats of the paint onto our mold and then let it dry. Then buffed with mold release wax and then sprayed a mold release onto it.

Before I offer specific advice, let me try to understand what you're doing. You've got foam on your seat pan and you want to integrate the seat pan with your final fiberglass seat/tail right?