Help me choose the best adhesive...

[Scout 30]

Rubber gloves don't make messes. People do.

[Group9]

Originally Posted by Scout 30

Rubber gloves don't make messes. People do.

Every time I get the 5200 out, my wife is just slightly more peeved than if she were to catch me with a hooker.

She says she cannot understand, for the life of her, how every time I use 5200 on the boat, some of it manages to migrate all the way to our house five miles away, where it gets on something important to her.

But, I do love 5200!

[atoll]

Originally Posted by Scout 30

Any particular polyurethane product that you recommend? Sounds like an interesting alternative to epoxy but there are a lot of different products. Also, I know with 5200 after you open a tube it starts to kick, even in the fridge, so having to throw away the whole container after a single use can get expensive.


FYI: Home Depot is the cheapest source for 5200 I've been able to find.

this is the stuff I use,Balcotan rapid,and regular

though all the expanding foam PU glues are pretty much the same,just different cure times.

link to the product details
http://www.robbins.co.uk/Pdf%20Files/pl5_balcotan.pdf

[blewett_john]

My preference is System3 GelMagic. It is pre-thickened, easy two-to-one mix, cures down to 55 degrees F, and is as strong as any West product.

I use the marked mixing cups to mix. I found that the small 4oz cups are good for small jobs.

Details at: SilverTip GelMagic - System Three Resins, Inc.

[Scout 30]

I couldn't find a US distributor for Balcotan. It looks like Gorilla Glue is a similar product that is available pretty much everywhere in the US.

[Scout 30]

These new epoxy cartridges that you use with a caulk gun sound pretty interesting. Sounds like a quick easy way to do a repair. Has anyone used one?

[Terra Nova]

Originally Posted by minaret

...What do you do for overhead layups?

My post was in answer to using epoxy glue. Now you are talking about laying up glass overhead? Quite a different application, for which I would suit up appropriately.

No way is foaming glue as strong as epoxy. No way.

I keep opened small tubes of 5200 (etc) for months, sometimes, by immediately capping the opening after use. When kept this way long enough, some cures near the tip. But this I quickly remove, with a drill, if necessary.

And I don't try to stick stuff to shiny, unprepped surfaces. Creating good bonds with epoxy normally requires cleaning and sanding the surfaces.

[Cheechako]

Originally Posted by atoll

I would actually recommend using a PU expanding foam glue for bonding wood strips to fiberglass,works well in all conditions ,even wet surfaces!

much much cheaper than epoxy,lighter,faster,cleaner,and just as strong once cured.
available in different cure times,5 minutes,and 30minutes are commonly available.

Polyurethane Adhesives Characteristics and uses.

Yep... if I were doing it again I might go this way... the nice thing is it expands as it cures, so lumpy surfaces get fully glued.
Epoxy can be great, or not work well at all... just depends on the surfaces you are gluing and fit. (yeah I know "operator error")
Two days ago I removed a small cleat glued with Gorilla Glue. To get it off with a hammer....it pulled some of the laminate with it!
There are better ones out there than Gorilla... but they are only available in larger containers...

[Terra Nova]

Originally Posted by Cheechako

...I removed a small cleat glued with Gorilla Glue. To get it off with a hammer....it pulled some of the laminate with it!...

This only proves improper technique. Had you used a sharp chisel and a hammer, you might have pulled an even greater amount of laminate.

For those who don't understand the concept of expanding glue, the small amount of liquid expands to potentially a very low density (lightweight) glue which, by the very nature of its low mass, must be many times weaker than properly filled epoxy. There may be many instances where it is convenient to use such adhesives. But certainly not where maximum joint strength is desired.

[Cheechako]

Originally Posted by Terra Nova

This only proves improper technique. Had you used a sharp chisel and a hammer, you might have pulled an even greater amount of laminate.

For those who don't understand the concept of expanding glue, the small amount of liquid expands to potentially a very low density (lightweight) glue which, by the very nature of its low mass, must be many times weaker than properly filled epoxy. There may be many instances where it is convenient to use such adhesives. But certainly not where maximum joint strength is desired.

Yeah... there are a lot of places I wouldn't use it for sure. For wooden strips bonded to the hull maybe for ceiling strips etc I might though. A lot of bonding area and good surfaces.
The commercial version of these glues (5 gal only) don't expand as much and are denser. The Gorilla version expands a lot.
We had a problem with a custom built DHS aluminum security boat, it had a large 8" "D" moulded rubber bumper all around the boat. The inside of this rubber nested on an aluminum channel shaped extrusion and the rubber was bolted on every 8" or so with a SS strap on the outside. Our "water challenged" servicemen had trouble with the Rubber moulding being ripped loose. (they didn't use fenders at the dock and the boat would bang on the dock all day) So we did some experiments at the shop with adhesives. Epoxy doesn't work well with rubber and metal at all. Pulls right off. 5200 not too good either. We ended up using the commercial urethane expanding glue. Our test was test pieces of hull mock up with the rubber attached with no bolts. A large sledge hammer was used to try to remove the rubber. We couldn't get it off. So then we retro fitted their boat with new system with the glue and the bolts.

[Scout 30]

I wonder if the polyurethane glue would work on hypalon. I've got to re-glue the rub rail & transom to my Avon & I'm not sure what to use.

[Cheechako]

Originally Posted by Scout 30

I wonder if the polyurethane glue would work on hypalon. I've got to re-glue the rub rail & transom to my Avon & I'm not sure what to use.

I'm not sure I would, you want something pretty flexible right?

[Terra Nova]

30--use Hypalon cement (it may be simple contact cement), available at marine chandlers.

[Scout 30]

Definitely needs to be flexible for the rubrail which would be hypalon to rubber. The transom would be hypalon to wood so that wouldn't need to flex but I wouldn't want something hard or brittle.

[Wotname]

Plus 100 on gloves, hot soapy water and vinegar!!!!!!!! Actone has no place anywhere near skin. In fact, I rarely use it anywhere when using epoxy.

As for expanding PU glue; this is a very versatile adhesive and for some uses can be used in place of epoxy. In some applications it is better than epoxy and in some it is not as good. It is certainly quicker and cleaner.

In all applications, it MUST be clamped (or screwed at the time of application) otherwise it will push the two surfaces apart during curing. It is very good where a gap filling glue is required AND the gap is difficult to fill during the application of the glue.

It IS stronger than epoxy when gluing tight fitting wooden joints. A tightly fitted wooden joint does not allow enough epoxy for the full strength of the epoxy to be realized. An epoxy joint must have some thickness of epoxy, not a very thin film. The expanding PU on the other hand is ideal for a tight wood joint if it can be tightly clamped during curing. The PU WILL expand during curing and if the main mass of the structure is well clamped, the PU will expand into the micro surface of the timber faces making for a very strong joint; more so than a thin epoxy film.