resin boat glue ?

[bjhbjh]

Hi,

I am building my first boat. The designer calls for epoxy as adhesive throughout, but my local supplier recommends a substance called 'resin boat glue' (RBG) which comes as a white powder that is mixed with 75 / 25 with water to make up a brown paste. It dries quite hard, almost brittle, its dirt cheep compared to epoxy and seems to stick stuff together pretty well. Presumeably its water proof (or they wouldn't call it boat glue) although I have yet to test it.

I can't find any info on this resin boat glue stuff and its adhesive properties as compared to epoxy. Can any one offer me any comparisons?

The principle at the supplier says he'd use the resin boat glue but if the designer calls for epoxy, I should use that. I guess he doesn't want the responsibilty.

I'm tempted to use the RBG but since the boat I am building is basically a wooden box with a curved bottom and that bottom is held on by glue and nothing else, I'd like some way to quantify these two options.

I have chosen this boat design as a simple build that will expose me to materials and techniques needed for more complex designs that I may or may not build in the future. This RBG issue is all part of the learning curve. Any suggestions?

Thanks,

Brian H.

[Bergalia]

It sounds very much like the marine glue which was sold as 'Cascamite'. White powder mixed with water - applied as a paste to one 'face' - and an acid 'catalyst' 'painted' to the other. Excellent stuff - highly recommended.
But I believe the name has been changed in recent years. Try a web search for Cascamite. And good luck.

[kengrome]

If you get the actual brand name of the product and/or the manufacturer's name you can probably learn more about it online through a google search. Your supplier's web site does not list anything called Resin Boat Glue. They do list this product however, which might be the one you're talking about:

Marine Resin Glue which sands easily, convenient and water resistant. The mixing ratio is a 3:1 mixing ratio (powder to water). Especially good for wood strip planking.

Note that this glue is "water resistant" not waterproof. If this is the glue you're talking about, I would not use it in the boat you're going to build. I think you should stick with epoxy like the designer suggests.

[KnottyBuoyz]

http://www.google.ca/search?hl=en&q=...le+Search&meta=

[bjhbjh]

Marine Resin Glue

Ya, thats the stuff, sorry my memory isn't what it used to be.

Note that this glue is "water resistant" not waterproof.

I guess we'll find out, I have just immersed a test piece.

Thanks for the suggestions etc,

Brian H

[keith66]

Regarding Cascamite, it is a urea formaldehyde glue in powder form, the hardener is in with it and is activated by mixing with water, it is a good glue for interior joinery and spars.
The glue refered to by Bergalia which needs a seperate acid hardener is Aerolite, this was made by Ciba Geigy and is the best glue in the urea formaldehyde class. The main problem with cascamite is it always has a myriad of tiny air bubbles in it unlike Aerolite which is used as a resin applied to one surface, hardener applied to the other.
For spars Aerolite can not be bettered and has the significant advantage over epoxy that it is not degraded by UV light
Aerolite was originally developed to build aircraft particularly the De Haviland Mosquito fighter bomber one of the fastest prop planes of ww2

[Bergalia]

Originally Posted by keith66

...Aerolite was originally developed to build aircraft particularly the De Haviland Mosquito fighter bomber one of the fastest prop planes of ww2

Thanks Keith. Years since I've used cascamite. Mixed with fine wood dust it alos made a great filler (not that my carpentry ever needed of a filler...just something I've been told by 'a friend' )

However I can add a little more to the Aerolite background. It was developed in a tiny shed at Duxford (Cambridgeshire). My mum worked for it's inventor a Doctor De 'something' (whose name escapes me) Bruno perhaps ? During her stint at Duxford the company built the 'tyres' for QEII's Coronation Coach - attaching the rubber to the rims with Aerolite.
I also have a small 'Ming' vase which the good doctor repaired with a 'new' gunge he was developing (Araldite). The vase lip was chipped and he clagged the gap and then fined it down on a lathe. Apart from the colour it's impossible to see the repair.

[keith66]

Cheers! there are several sayings to go with glue often used in the real world "In glue and dust we place our trust" or "If the joint does not fit, fill it up with glue and S***" nice to learn of the development of the stuff!

[Bergalia]

It's come to me - Dr Adrian De Bruyne. Lovely feller - born in Chile of Dutch parentage.

[Trevlyns]

So Keith, do you know whether these glues are available in our area? Do they still go under the same brand names and do you perhaps know of a local supplier?
Ps, sorry I missed you Sunday – went out to collect an outboard I bought on e-bay! Link up with you this weekend mate.

[eponodyne]

Borden Wonderbond has been a standard for years for those sensitized to epoxies. And there is a particularly fine resin glue available in the UK--made there, I believe--which is almost completely unavailable to we poor punters in the former Colonies. Aerodux? Something like that. Good gap-filling properties and able to be applied at temps down to 38*F or so (balmy June afternoon for bergy), tolerant of higher moisture content of wood, not that hideous purple... Help a brother out here.

[thudpucker]

Brian, on your bottom application:
I helped a guy build a bunch of McKenzie river drift boat (Copies) and later on I took some clients down river in the boats.
We did not glue the bottom to the boat.
We used a million bronze wood screws in a zig-zag pattern, no more than an inch or so apart.
I dont think the bottoms leaked very much if any at all.

We did it this way because the boats were skidding and bouncing off the rocks in the river and the bottoms had to be replaced almost every season.

I believe in screws, but I'm only mildly impressed with glue where you dont use any screws as the 'suspenders' for confidence.

[Landlubber]

Resorcinal glue is another two part powder/ liquid glue. Used in Marine grade plywoods for years.

Have a look at the layers of marine ply and you will see the red line. I built a 32 foot yacht in the 60's with it and it is still perfect.

[PAR]

Since the invention of epoxy, there as been only one real marine glue. Nothing compares when it come to less then perfect fitting joints (gap filling), room temperature cures, minimum pressure of the jointed parts, water proofness, flexibility, bonding fabrics, bonding most other materials, etc.

Bjhbjh, the biggest issue home built boats have is the novice making decisions he shouldn't, such as changing adhesive recommendations from what is spec'd in the plans. If epoxy is called for, then you'd be very hard pressed to find an equal or better substitute. I started adulthood as a chemical engineer - do yourself a favor and make changes to the things you have a full grasp of (a complete grasp). Those things that you don't fully understand (like the physical properties of epoxy) should be left to those that do. Nothing personal, but you're playing with fire if you make these level of substitutions.

[Landlubber]

PAR, well put my friend. And quite correct, as long as he is smart enough to follow the directions, nothing will go wrong.

Mix proportions are critical when using epoxy glue, so for instance, if it says 1:3, then make one pile of hardener and three piles (equal to the hardener pile) and then mix all four piles.
Do not fall for the trick of making one pile of hardener and then another pile three times the size, as it rarely will be.

I have used epoxy glues for over 30 yeras with never a failure on a glue line from it, it truely is a remarkable glue when used correctly.