fiberglass to aluminum

Discussion in 'Materials' started by garrick, Apr 13, 2008.

  1. garrick
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    garrick Junior Member

    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.
  2. Landlubber
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    Landlubber Senior Member

    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.
  3. the1much
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    the1much hippie dreams

    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.
  4. garrick
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    garrick Junior Member

    ok, not what i wanted to hear , thanks for the info!
  5. rwatson
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    rwatson Senior Member

    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
  6. the1much
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    the1much hippie dreams

    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.
    wowz,,,dem sum big werds,,hehe
  7. dragonjbynight
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    dragonjbynight Senior Member

    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.
  8. Dizchord
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    Dizchord New Member

    Rather than explain why it can't be done, I'd like to explore ways that it could be done. One thought: drill holes in a spiral pattern around the aluminum tube to be joined, weave carbon fiber and/or glass (straight roving from a spool would be needed) through the holes, and bond that into a carbon or glass sock, and tab into the glass/epoxy however you need. I think that would probably be the strongest method to make a waterproof bond between the two. I could be very wrong, but I'd be willing to test it.
  9. ondarvr
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    ondarvr Senior Member

    It may be a bit late, the OP hasn't been around in 7 years.
  10. Dizchord
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    Dizchord New Member

    Yeah, I noticed that after I posted. Still a good idea though :p
  11. Ad Hoc
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    Ad Hoc Naval Architect

    Sorry incorrect.

    We've designed and built aluminium vessel with structures that are bonded. All to Class rules too. They are all silane-based bonding and works well. Modern adhesives do work. It is all about the preparation, that's the key to it all. Get it wrong and it fails. Most silicone based such as Sikaflex works a treat.

    We have also successfully bonded composite panels to aluminium vessels (Patrol Boats to Crew Boats to Passenger Fast Ferries), again, all to Class rules. All that is required to satisfy Class rules is a method to prevent peel at the ends.

    If you're talking about some Micky Mouse production because it is snake oil salesman cheap and in a dodgy back garden shed, most likely will fail and badly. But if ones use the correct products and preparation - it works.
  12. gonzo
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    gonzo Senior Member

    On a small boat like the OP described, you can use the hull as a mold to laminate a shelf. Remove it after it cures and bond it to the hull. There are many adhesives that would do the job. For example 5200.
  13. mydauphin
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    mydauphin Senior Member

    I have used 5200 to bond aluminum to aluminum to reduce noise or provide some isolation. If you prep aluminum it basically has to be cut off. Use the slow cure. It takes a while, like more than a week. But the bond is ridiculously strong.
  14. latestarter
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    latestarter Senior Member

    I read about a technique online a couple of years ago which I and others have tried.

    Spread a layer of epoxy over the area, wear suitable epoxy resistant gloves, take a piece of abrasive paper and rub it over the area.
    This removes the aluminium oxide and the epoxy stops air getting to the surface so the epoxy bonds directly to the aluminium before it can re-oxidise.

    I used it to bond timber to aluminium, however if left to go tacky you could add layers of fibreglass and epoxy.

    Whether it is suitable for highly stressed, life critical situations I do not know.

  15. PAR
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    PAR Yacht Designer/Builder

    I remember this post from way back then and I didn't bother replying at the time, because of the easily explored nonsense that was being tossed about.

    Aluminum, steel and just about every metal can be bonded, hell explosively if necessary, though more commonly, with adhesives and the strong inter-molecular bonds, make silanes (saturated silicon) a good choice. There are also several other adhesives (epoxy, polyurethane, etc.) that are quite commonly used with metals. The jet airliner that flew away with their logic, on some of the posts above, likely had it's aluminum wings attached to the fuselage with epoxy.

    Specifically, aluminum can be bonded to about anything relatively easily, given appropriate prep. Ditto most other metals and dissimilar material bond situations.
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