fiberglass to aluminum

[garrick]

I was going to redesign a jon boat that I have, I was going to give it a front and rear deck, and redesign the hull a little so that I can be comfortable standing on it. will fiberglass stick to aluminum? or steel, idk what it is but i'll find out. I'm not looking for criticism i'm just asking if I can get fiberglass to bond with steel or aluminum.

[Landlubber]

Basically the answer is no, now having said that I am sure there will be buckets of people that will have stories of how long they have had the opposite occur, but really, the answer is still no.

[the1much]

no, no, no,,,like land said,,,you'll find all kinds of people who say yes,,,and some that say its been done ( ive done it,,and it lasted about 6 months) but the truth of the deal is,,the ONLY way they can get alum. to stick to itself is to weld it,,,THATS it,,no adhesives have been "proven" just for alum. to alum,,,it'll be decades before they come up with something that'll bond stuff like glass to alum.

[garrick]

ok, not what i wanted to hear , thanks for the info!

[rwatson]

of course sticking fibreglass to aluminium is not the same as a strong, waterproof join to aluminium - which IS possible with good design and the right goo

[the1much]

Polyester over epoxy


By Jeff Wright

Most production fiberglass boats are made with polyester resin. WEST SYSTEM epoxy is a wonderful material for repairing polyester fiberglass boats. One reason for this is the ability of epoxy to form a stronger mechanical bond to a damaged laminate than polyester resin. Epoxy also provides a better moisture barrier than polyester resin.
Understanding the materials
Polyester resin laminates achieve their highest strength when the bonds between layers of fiberglass are chemical or primary bonds as opposed to mechanical or secondary bonds. The manufacturing process for polyester boats has been developed so that a chemical bond exists between the gelcoat and the laminate. When a polyester boat is built, polyester gelcoat is first sprayed onto the mold surface. The first layer of the laminate is then applied to gelcoat, which has not completely cured. The two layers eventually cure together with a chemical bond between them.

Applying gelcoat to a cured laminate relies on a mechanical bond. Because of the difference in curing chemistry, it is not possible to achieve a chemical bond between epoxy and polyester gelcoat. We developed some tests, to determine whether or not the mechanical bonds achieved between gelcoat and properly prepared, cured epoxy were strong enough to achieve a durable repair.
so west system says we're all right,,,secondary and mechanical are the same thing,,so that kinda makes us a little wrong too,,hehe
some more alum stuff
(1) Department of Materials Science & Engineering, University of Cincinnati, 45221-0012 Cincinnati, Ohio
(2) Present address: Department of Polymer Science & Engineering, University of Akron, 44325 Akron, Ohio

Received: 21 December 1993 Revised: 1 July 1994
Abstract The adhesion-in-peel test was used to determine peel strength and adhesion characteristics of a cured-in-place silicone elastomeric joint sealant on aluminum substrates. The sealant used was a Dow Corning Type 3145 RTV Adhesive Sealant. The results showed that the silicone sealant had poor adhesive bonding to the untreated aluminum. Plasma polymerization of hexamethyldisiloxane (HMDS) onto the aluminum was seen to move the locus of adhesive failure to being between the plasma film and the silicone. Plasma polymerization of HMDS with oxygen carrier gas produced excellent adhesion and cohesive failure in the silicone was observed.
http://www.springerlink.com/content/...c4879b5d6&pi=4
wowz,,,dem sum big werds,,hehe

[dragonjbynight]

Just my opinion, but if your talking jon boat, 12-15 ft range, You could place wooden stringers, which can be bonded with fiberglass. That being said, it sounds as if your making more work for yourself. If you have to place wooden stringers anyway, a ply deck would be much simpler and inexpensive to place. cut, treat and place. you could glass the deck for more strength or wear prevention, but thats going to add more weight. well, thats my 2 cents worth anyway.