Fiberglass on aluminum

[duxbait]

I've got a 10' aluminum bateau that I use as a tender/clam skiff. The grooves (chines?) on the bottom have worn out in some places, mostly from being dragged across mud and scraping rocks. I've used marine-tex to fill in the holes, but this only lasts a little while. Seems like I wouldn't be able to get fiberglass to adhere to the aluminum. What do you guys think? I was thinking about laying some fiberglass strips over the chines with epoxy. If this isn't an option I guess I'll 5200 some starboard strips to the bottom with maybe a few screws. Thanks for any advice.

 

[nickyp]

I do know that 5200 or silicone, or 4000does not stick to starboard. It is very hard to find something off the shelf that will stick.
Maybe there is something more specialized.
Would it be too expensive to get a welder to fix you up?

 

[duxbait]

I do know that 5200 or silicone, or 4000does not stick to starboard. It is very hard to find something off the shelf that will stick.
Maybe there is something more specialized.
Would it be too expensive to get a welder to fix you up?

Probably not going to get it welded. The skiff has work for a long time by applying marine-tex and metal tape once in a while. It's something I don't worry about too much, but was thinking a more permanent solution would be nice. And thanks, didn't think about how 5200 won't hold starboard.

 

[nickyp]

Maybe something like Lexel might work.
Especially if you screw it on, the Lexel would just be a gasket.

 

[nickyp]

I'm just thinking of quick fixes here...
Maybe sand the aluminium, and starboard, wipe down and paint with contact cement.
Ley dry thoroughly, and then screw and bed together with whatever.

Contact cement was a temporary solution to a problem my boss had on his racing sailboat.
It has some kind of alloy keel that primers and bottom paint did not want to stick to.
He applied contact cement, then antifoul, and it worked quite well.

Shit, maybe glass will work.
I'm sure someone will tell you if it will

 

[Toolate]

II've seen these on small FG boats and inflatables never aluminum but I would start by finding out what they use to adhere them with and try that.

Any way to just rivet some aluminum pieces over the chines with some bedding caulk under them? Sounds cheap and easy.

 

[Leprechaun]

years ago (30 ish) one of the old time lobstermen glassed his 14 / 16 ft aluminum skiff over. Wish he was still around to ask but I know what he did was not very fancy. If I remember correctly he just did some light grinding and glassed it over (2 or 3 coats maybe ??).. I do know it held up very well for years.

Maybe one of the glass guy's might be able to help out ??

 

[Keelboater]

Use West System 860 Aluminum Etch Kit to prep the boat, and then West System Epoxy and West System glass fabric. The fabric is supposedly treated with a chemical coupling agent designed specifically for epoxy use, making it slightly different than conventional polyester fiberglass fabric. The result is a superior bond to aluminum. At least that's what I was told by them.

 

[pugsley]

you can glass aluminum, you need to get it roughed up first, sand blasting works real good, or a real real rough sand paper on a grinder.

 

[nickyp]

Use West System 860 Aluminum Etch Kit to prep the boat, and then West System Epoxy and West System glass fabric. The fabric is supposedly treated with a chemical coupling agent designed specifically for epoxy use, making it slightly different than conventional polyester fiberglass fabric. The result is a superior bond to aluminum. At least that's what I was told by them.

A binder is used to help hold fiberglass together.
It is styrene soluble for use with polyester and vinyl ester resin.
West systems fiberglass uses a binder that is soluble in epoxy.
West system does state that styrene binder is compatible with epoxy. It does not dissolve, but stays in suspension, and is sealed by the epoxy. The only downfall is that the cloth will be less pliable in laying up.

 

[duxbait]

I think I'm going to do a rough grit sand and glass over. Seems like it will grab. Worst case, it doesn't hold and I try some of your other recommendations. Thanks for the tips.

 

[pyrofan]

I have glass over aluminum on a couple of different projects,using polyester resin, all with good results. As with most projects preparation is the key to success.

I always try to wash any area to be glassed, to try and get rid of any contaminates...oil film, release agent ect... then sand with 60-80 grit paper by hand or machine. When done wipe done the area with acetone let dry, then you can start glassing.

 

[bestfish]

I recently repaired some aluminum with poly resin. I ground down the area with 36 to make it rough, body filled the rotten spots and faired. Then I etched the whole surface with white vinegar. Rinse with acetone and glass. Came out really good. I thought the vinegar trick was a myth until I did it. You can see tiny bubbles and smell it doing something.

 

[Brooksie]

My 2c.
1) 5200 will stick to anything except polyethlene. Why not go over the spray rails w/ aluinum angle stuffed with 5200 putting some bricks on them while they set.
1) If you want a surface that can be dragged over rocks and sand for years, gob on epoxy thickened with silica (Cabosil) you won't live long enough to wear through it. Sand and thinner wash first of course.

 

[Bill]

My 2c

Depending on what it's worth to you . The way to fix it is to use Devcon aluminum epoxy.. Ive used it on pump shafts that were worn out and then machined them down to original thickness.

Devcon - Aluminum Putty F from Seton.com, Stock items ship TODAY, Custom ships FAST!

 

[Toolate]

1) If you want a surface that can be dragged over rocks and sand for years, gob on epoxy thickened with silica (Cabosil) you won't live long enough to wear through it. Sand and thinner wash first of course.

Really? No glass in it? Interesting. I used this stuff and other than being a pain in the ass to mix in it makes for a nice thick/trowelable putty mix. I could use this if its as durable as you say.

 

[sailor of fortune]

I don't think you will have any problem with your plan to glass this. The vinegar etch trick is a new one on me, I like!

 

[hatterasser]

Check out g-flex epoxy by west supposedly bonds to aluminum well then glass over with west

 

[duxbait]

So I glassed over yesterday. Sanded it rough, then cleaned it with solvent. Layed on fiberglass tape with epoxy. Added a little extra epoxy at the end to give it some more thickness. It seems to have stuck well. It think the concave shape op the strakes and the abrasion of the sanding will help it to hold fast. I had all materials already so it was a cheap and easy job.