Some (very quick) advice on Fiberglass (like, before this resin hardens quick)

[Petorius]

The do it right approach is to use modeling clay on the inside of the part you want to replicate, then glass over your model. I'd also recommend using wax paper rather than a plastic wrap between the model and new part.

The part you want to look pretty is the outside of your final product, not the inside of the final product. If you clayed the inside of the original, then glassed over your clay, the inside of your final product would come out nice, but the outside would just be a mess of epoxy.

[jasnmar]

So, use a combination of the foam as blocking and clay for details and mold the outside if you want. It'll be much harder to lay the glass on the "interior" surface than an exterior one (more bunching, harder to access).

You may be using too much resin if it's just a "mess of epoxy". Glass is usually a "multi-pass" application. More thin layers >> One big globby layer (but there's a lot more waiting as well).

[loudbeard]

The part you want to look pretty is the outside of your final product, not the inside of the final product. If you clayed the inside of the original, then glassed over your clay, the inside of your final product would come out nice, but the outside would just be a mess of epoxy.

OK, I'll buy that.

[Ductard]

The part you want to look pretty is the outside of your final product, not the inside of the final product. If you clayed the inside of the original, then glassed over your clay, the inside of your final product would come out nice, but the outside would just be a mess of epoxy.

Molding the inside is a non-starter anyways. It's too rough in there, for reasons having to do with how the pan I'm molding from was made.

Either way, none of this really needs to "look pretty." The back half is going to be sitting between the exhaust cans and scrunched between the oil pan and the cans. The front half is going to be under the side-fairings (which are 1 piece deals unlike the armour bodies for most bkes I've seen and go all the way from top to meeting each other under the radiator.)

Maybe the very bottom (where the stock fan ducting will be covered) will be visible when I'm at full lean but I'll be sure to tell Arcy not to take any embarrassing shots of my underbelly.... :-)

The only cosmetic goal here is to make look solid enough to where I gon't get looked at like I have two heads going through tech, but clearance/fitment is the real goal.

That, and it has to be fluid-tight to hold the Andre I'll be drinking out of it after I step off the podium.

[Petorius]

You may be using too much resin if it's just a "mess of epoxy". Glass is usually a "multi-pass" application. More thin layers >> One big globby layer (but there's a lot more waiting as well).

I am definitely guilty of this. My tail has basically no flexibility now due to the amount of resin I gobbed all over it.

[Ductard]

I am definitely guilty of this. My tail has basically no flexibility now due to the amount of resin I gobbed all over it.

Guilty here too. I actually used resin jelly for my first repair job of the armour bodies. Needless to say I could probably shed a few pounds now....

[scubasteveRR]

I've done a fair amount of fiber-glassing and tinkering with creating parts, if i were creating a rough part that didn't need to look pretty i would do this..

Step 1. cover the outside of the piece in first.. blue painters tape.. then duct tape... (blue tape releases easy from your part, and fiberglass releases from duct tape)

Step 2. now cover the part in about 3 layers of fiberglass and resin, crossing the fiberglass mat with each layer

step 3... get one of those huge space saver vacuum bags and put some release agent in the bag, (i've used a small amount of olive oil before if you don't want to buy actual release agent) put the wet fiber-glassed part in bag, seal it and vacuum it.

bam, you have your rough part now sand and paint to finish.

if you want it to look really nice you'd have to do what these guys are saying in using Styrofoam and clay and also using a vacuum bag or making a two part mold out of fiberglass which is on a whole other level, but i've done it once with a much smaller piece ( the good part about these is you can reproduce for other in your situation)

[Eric Baker]

Can't you use Plaster of Paris to make a mold? I swear I've seen that somewhere. The problem with clay is keeping it rigid between making the mold and laying up the fiberglass.

[Ductard]

Edit: Nevermind - acetone or laquer thinner according to the resin container. Missed that earlier.

Question - is there anything that I can use to clean the resin off the brush so I don't have to chuck it every time?

The brushes I'm using are ~$1.50 each, but as it's going now, I'm doing it a little at a time and it could add up. Would rather not chuck them every time if there's some way to clean them.

[jasnmar]

Acetone.

Wipe away as much as you can with mixing brushes, paper towels, whatever. Wipe away some more.

Pour some acetone in a solo cup. Dip and shake the brush for 30 seconds, spreading the bristles as much as possible.

Wipe the brush with paper towels. Dispose of the Acetone and repeat.

You guys have shortened your cheap brushes, right? Carries less material, but is stiffer and better at pushing the resin in.

[Garandman]

On sailboat repairs they use "vacuum bagging." They cover the area with a sheet of plastic, create an opening and hook a vacuum to it. This provides uniform pressure and helps get good wet out.

Some people make molds from RTV silicone rubber, you can pour it on top, let it cure, and the flexibility makes release easier.

[RandyO]

a friend of mine made a carbon fiber fuel tank for his ultra-light my starting with a block of styrofoam then laying the carbon fiber around the styrofoam mock up that was a solid block carved into the shape, then putting gasoline in it to melt the styrofoam out of the inside

[tropicoz]

Why not line the original pan with Saran Wrap like you did, then use expanding foam to make the mold? Then use that to lay fiberglass?

[Ductard]

Why not line the original pan with Saran Wrap like you did, then use expanding foam to make the mold? Then use that to lay fiberglass?

I think I'm happy with it as-is. Will find out when I try to mount it next weekend.

[jasnmar]

Why not line the original pan with Saran Wrap like you did, then use expanding foam to make the mold? Then use that to lay fiberglass?

Still an interesting idea. I had not considered that.

[Ductard]

Still an interesting idea. I had not considered that.

Oh, definitely. It's past my bed time and in my haste I neglected to give props for the idea.

Thanks to everybody for the ideas. There's still a chance i might make a mold for the future, or try to make some to sell on the 1299 forum so feel free to share.

[CBR929RE]

if you're gonna add any more layers to what you already have then sand the dried part first. it'll stick better. mock up what you have now and make sure it fits before you go and do more work to it. I think you're going about this the same way I would. I made an undertail for my bike to keep water off the electronics because the motoholders subframe doesn't use the stock undertray. I had to make a mold out of nothing for mine.

where is IslandBoy? this is his area of expertise.

[02redhawk]

lookup hotwire foam

Cut styrofoam?