Fixing Delaminated Ply?

Little Rascal

Little Rascal

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One of the ply slats in my new (to me) tender is delaminating. Not the face veneer so much, but one of cores. It just needs clamping/gluing before I revarnish....

I know the 'proper' fix is thinned epoxy, but I don't have any and I don't need very much. It's hardly worth the cost/waste of buying some...

Any suggestions for other glues? Can you thin cascamite enough do you think? Or even (proper bodge) waterproof PVA?
 
Little Rascal said:
One of the ply slats in my new (to me) tender is delaminating. Not the face veneer so much, but one of cores. It just needs clamping/gluing before I revarnish....

I know the 'proper' fix is thinned epoxy, but I don't have any and I don't need very much. It's hardly worth the cost/waste of buying some...

Any suggestions for other glues? Can you thin cascamite enough do you think? Or even (proper bodge) waterproof PVA?
Click to expand...

PU glue
"Joiners Mate" messy stuff but air cures & expands as it cures
 
Whatever you use, even if you use the proper stuff (!) you'll need to get the wood thoroughly dry before gluing, which may not be easy. You then have to prevent moisture ingress. It may be easier just to make a new one

As my Zodiac gets put away damp after use (lives in a basement at the sailing club, so no way to dry it before we go home), I've accepted that my battens will have a limited life and replace them as required. Proper marine ply and a soaking in epoxy before finishing ensures a reasonable life. I'll need new at the end of the season ('cos I'm too busy sailing to do it now), but the homebrews lasted longer then the originals.
 
Stemar.... It's pretty dry at th emoment, been in a garage for a few years. Also small enough to go in my airing cupboard!

At £20 for 500g of Balcotan, Im tempted to just use PVA to seal it and accept I'll need to make a new one at some point...
 
Some of the polyurethane glues are moisture cured ... You make the wood moist before using them.

I watched someone using Gorilla glue a few weeks ago and he had to dampen the wood first.

Also the joiners mate just mentioned.

I guess moist does not mean saturated though.
 
Not all brands of PU are equal. I've used Balcotan and Titebond on a very wide range of jobs with total success. I used to use a Dow-Corning product called Geocel successfully, but the last two packs I bought both seem to foam excessively, have a very short open time and are a complete pain to clean up afterwards. They must have changed the formulation so I don't buy it any more.

I once had to use a product called Lumberjack PU which was truly awful - it foams so much and so quickly I really can't think of any application it is suitable for. I threw the rest of the pack away in disgust!

As Vic says, they're mostly moisture curing, so you don't need to dry the wood out completely. While they are gap-filling, the cured PU in such gaps has no strength to it (unlike an epoxy mix), so you'd need to clamp the joint.

Titebond 4 fl oz bottle is around £5.50, 8 fl oz £10 and 12 fl oz approx £13. No need to buy a large bottle of Balcotan.
 
I always buy epoxy in 3Kg lots, and always have at least a Kg handy - so I've never been in your situation ... but if I ever was ... then I'd buy a couple of packs of epoxy from the 'pound shop*', and dilute the contents of each tube with (say) 5 or 10% acetone or cellulose thinners, before mixing 'em together.

Then slurp away ....

Just checked my stock of 'el cheapo' epoxy - £1 for 28g (double syringe job) - shouldn't take more than one or two packs ?
 
electrosys said:
and dilute the contents of each tube with (say) 5 or 10% acetone or cellulose thinners, before mixing 'em together.

?
Click to expand...

I do not reccomend thinning the components BEFORE mixing them as I have had issues with the mix failing to go off correctly.

I mix the epoxy THEN add thinning or thickening agent. BTW I believe mthelayted spirits is the reccomended thinner but I have also used toluene with success.
 
VicS said:
Some of the polyurethane glues are moisture cured ... You make the wood moist before using them.

I watched someone using Gorilla glue a few weeks ago and he had to dampen the wood first.

Also the joiners mate just mentioned.

I guess moist does not mean saturated though.
Click to expand...

I was using some kind of PU glue yesterday and the instructions said 'Wipe one surface with a damp cloth'.
 
TQA said:
I do not reccomend thinning the components BEFORE mixing them as I have had issues with the mix failing to go off correctly.

I mix the epoxy THEN add thinning or thickening agent. BTW I believe mthelayted spirits is the reccomended thinner but I have also used toluene with success.
Click to expand...

Toluene is used with polyester.
Acetone or Cellulose Thinners are used to dilute Epoxy (and for cleaning brushes etc).
Methylated Spirits isn't used for thinning either of 'em.

The reason I said to thin before mixing, is that unlike regular epoxy, the stuff I'm referring to is 5 minute epoxy, and you really haven't got time to buqqer about once it's mixed - every second counts.

Electrosys - when you say the pound shop... do you mean any old pound shop?
Click to expand...
Pretty much (afaik) - I buy my 'el cheapo' epoxy (the brand name is '151') from Scooby-Doos in Spalding, but I've seen the same stuff at many boot sales, so I reckon it's available in most places. It's not the best epoxy, by a long shot - sets too brittle for my taste - but it's dirt cheap. The next cheapest is Wilko's own brand, about £3.50 for 2 x 15ml tubes. Araldite is now about a fiver (I believe) - haven't bought any for years. Love it - but too dear for ordinary jobs.

BTW - if you use '151' epoxy - remove the black strip between the plungers before you press 'em down. They don't tell you this on the packet, and if you don't the plungers can jam.
 
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electrosys said:
Toluene is used with polyester.
Acetone or Cellulose Thinners are used to dilute Epoxy (and for cleaning brushes etc).
Methylated Spirits isn't used for thinning either of 'em.

.
Click to expand...

OOPS My bad

your dead right = acetone for epoxy is the recommended thinner

Good article here on the pros and cons of thinning West Sytem epoxy

http://www.westsystem.com/ss/thinning-west-system-epoxy/


HOWEVER both toluene and methylated spirits work and work well for me amd many others in industry with meth ESPECIALLY useful where a relativey slow rate of of evaporation is desireable when fabricating or repairing composites.
 
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TQA said:
OOPS My bad

your dead right = acetone for epoxy is the recommended thinner

HOWEVER both toluene and methylated spirits work and work well for me amd many others in industry with meth ESPECIALLY useful where a relativey slow rate of of evaporation is desireable when fabricating or repairing composites.
Click to expand...

I stand corrected - iso-propyl alcohol (near enough meths ...), toluene, xylene and naptha are listed (at http://www.epoxyproducts.com) as known thinners.

Although acetone is usually given as the recommended thinner, in practice cellulose (lacquer) thinners is probably the easiest and cheapest of any of these to obtain - around £10 for 5 litres from any vehicle paint suppliers.
 
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