Fibreglass work

[Rogue]

Hi guys, Ive recently bought what I beleive to be a fibreglass Prather Lapcat 3.

I have taken all the paint off the hull to paint it in Pro Drive Subara WRX blue.

What I need to know is what the best way to fill cracks and holes are, I have tried Araldite (epoxy) but when I sanded it back it came away.

The other option I thought is to use a builders bog which should hold to fibreglass with the paint but it is not good for big structual parts.

Is the best option just fibreglass resin? (Im worried it will be the same as Araldite)

What do you guys use, and since Im in Australia what would I be able to use here?

I will post some pictures when I can if it helps.

 

[rmprecision]

Hi guys, Ive recently bought what I beleive to be a fibreglass Prather Lapcat 3.

I have taken all the paint off the hull to paint it in Pro Drive Subara WRX blue.

What I need to know is what the best way to fill cracks and holes are, I have tried Araldite (epoxy) but when I sanded it back it came away.

The other option I thought is to use a builders bog which should hold to fibreglass with the paint but it is not good for big structual parts.

Is the best option just fibreglass resin? (Im worried it will be the same as Araldite)

What do you guys use, and since Im in Australia what would I be able to use here?

I will post some pictures when I can if it helps.

Hi Matt

sorry what i should have said the other day was use vinal ester resin, I think this should work.

Being a epoxy layup a resin called Dekeraine would work aswell.

To make a paste filler mix the resin with a little talc powder (brute33 or old spice to make it smell nice )

Should mix up like the builders bog which is nearly the same product.

Catch up later Jason

 

[Foolwitools]

Hi!

Prather boats are definately epoxy-glass............ polyester (fiberglass) resin will not bond to epoxy glass.

I assume that you cleaned the repair area with acetone, alcohol, or laquer thinner before applying the epoxy......... if you used a petro-based solvent or if the repair area had fuel soaked into it or anyting else that could leave residue this may be your problem.

If the cracks you are trying to fill are tiny hair line cracks. you will have to make the surface of the crack a little wider (2-3mm) to give the filler( epoxy) a place to adhere. a wire brush on a dremmel will do a nice job. You only want to scratch the gell coat. try not to get into the cloth.

If the area is weak, it will only crack again. you might think of backing up the area from the inside with a "bandage" of light glass cloth and epoxy. this will help limit flexing and further cracking.

Use slow setting epoxy and let it cure at least over night. if the surface is gummy or you can push the tip of a knife into the epoxy, it is not ready yet. If the epoxy is not fully set, it will peal away as you are sanding it. Thinly spread epoxy takes longer to cure than the unused stuff in the mixing cup.

Hope this helps you. these are methods that have worked for me.............. if anyone has a better idea, please let me (us) know

Good Luck,

Bob the Fool :blink:

 

[MalaysianFlyer]

Not sure if its a better idea or not, but the original instructions that come with the prather boats advice you to use putty (Bondo or similar) to fill the pinholes.

The guys over here who bought the Lapcat I recently, all used putty and no problems so far.

Might be better to wait for more ideas to come in before trying it

 

[RodneyPierce]

Not sure if its a better idea or not, but the original instructions that come with the prather boats advice you to use putty (Bondo or similar) to fill the pinholes.

The guys over here who bought the Lapcat I recently, all used putty and no problems so far.

Might be better to wait for more ideas to come in before trying it

Bondo or spotting and glazing putty. Seems to work great

 

[HOOTERS Racing]

mate i only use west system epoxy resin 105 with west system fast hardner 205

mixed 5 to 1 (5 resin to 1 hardner then i add west system microlight 410

easy to sand and shape hope this helps

regards

ian