What Glue for Plywood Repair?

Zagato

Zagato

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I am hoping to do this before I sail next weekend so taking into account the temperatures are quite low at the moment. Despite water sitting on top, the wood is dry.

Cascophen, Aerodux and the West system have been suggested by one ex wood boat builder so far! Cascophen doesn't seem to hold up well though when doing a search on past posts!!

IMG_2775.jpg


The layers have seperated along this bit... I suppose quite a bit of old resin would still be inside, no way of cleaning it out, so it may not be so much wood to wood either!

Force4 sell Collano, suggestions welcome. Thanks

http://www.force4.co.uk/9726/Force-4-Collano-Semparoc-Adhesive.html
 
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That polyurethane would be suitable - although think that one is very expensive. Problem you are going to have is cleaning all the old adhesive out of that join and then clamping it. Although poly does not need high clamping pressure, it expands as it cures so if you just squirted it in the gap it would fill it but would have no strength.

An alternative is to clean it out and fill with thickened epoxy which will be stronger, but still won't close up the gap without clamping.
 
I repaired a de-laminating laminated tiller in situ with Joiners Mate, a two part adhesive that is relatively easy to apply in this sort of situation as activator is sprayed on after application of the adhesive.

Recommended by Sailorman and I have found it excellent in a variety of uses.

Its the Mitre Bond:

http://www.screwfix.com/p/geocel-joiners-mate-mitre-bond-50g/63935
 
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I love Epoxy

it has never let me down

and can usually be persuded to go off with a bit of warmth

I would also get a hot air gun and dry everything out as well as I could before applying

any epoxy exposed to UV will change colopur so your nice clear stuff will go snot yellow

Dylan
 
I have recently used Collano Semperoc with good results. Easy to work with, no messing with mixing, reasonably good at gap filling, uses moisture to cure. Frankly I wouldn't use epoxy on anything that has the potential for inherent dampness as you will have inside those laminates. See ECS07 rudder repairs at www.eastcoastsailing.co.uk.

It's a lot of glue to buy for a repair that size though. Shame I have half a pot here but there is no practical way of getting you some of it.
 
Polyurethane such as Gorilla glue. Fully waterproof and cure activated by moisture. It does need clamping though even though it is foaming you need to close the gap as tight as possible.
 
I would be happy using either epoxy (if completely dry) - initially un-thickened and brushed around, then thickened with filleting powder, or Collano Semperoc which I have used with great success recently. There is a fast and slow setting version, fast seemed to work excellently and once set is tough yet slightly flexible
 
Dylan,

I have used it quite a bit now and not had any failures. As said on the other forum you need one side moist and then high clamping pressure. I use ratchet straps or g clamps and leave the work over night at least. The whole lot is covered with polythene sheet to protect the work surface and clamps/straps.
 
Think the problem with the OPs job if I read the pic correctly is that it is a laminated capping on top of a grp moulding and there does not seem to be a way of clamping it without boring some new screw holes and then plugging them. Will still have a problem cleaning the faying surfaces.
 
Thanks for the replies, Just to clarify a few points;

the wood is bone dry at the moment,
as guessed cleaning out the gap is impossible it's too narrow,
the wood panel (forgotten technical name for it!) is about 10" in depth front to back so a G clamp could be put on it if it would go over the bar - yes I don't know name of that either :rolleyes:

A new one is about £400 :eek: as it is curved and needs a gig to make one or same price off the shelf. I am wondering if a good permanent fix would be to use a glue whilst also bolting through spreader plates of some sort either side and clamping it all together with s/s nuts & bolts.
 
You still seem to be having doubts, here's a couple of suggestions that might help?
1. The separation gaps can be raked out using a hacksaw blade. Wrap tape around the 'handle'' end.
2. Take pieces of inch timber or say 3/4 inch ply and cut long vee slots in an end. With simple cunning these can be your designer G cramps.

Add glue of your choice though epoxies and their fillers are so versatile these days....

hope that helps a bit.
 
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Zagato said:
Thanks for the replies, Just to clarify a few points;

the wood is bone dry at the moment,
as guessed cleaning out the gap is impossible it's too narrow,
the wood panel (forgotten technical name for it!) is about 10" in depth front to back so a G clamp could be put on it if it would go over the bar - yes I don't know name of that either :rolleyes:

A new one is about £400 :eek: as it is curved and needs a gig to make one or same price off the shelf. I am wondering if a good permanent fix would be to use a glue whilst also bolting through spreader plates of some sort either side and clamping it all together with s/s nuts & bolts.
Click to expand...

Has it delaminated right across or just on the side you can see in the pic? From memory it overhangs the coaming so you can get clamps on part but not on the bit that sits on the grp. The ideal if the wood is sound is to take the lamination off the grp, open up where the glue has failed, clean it and reglue round a former using epoxy.

If the failure is just in the area shown in the pic then clean it out with a hacksaw blade, force in epoxy thickened with silica and microballoons and clamp it together with countersunk screws with matching plugs.
 
Thanks for the answers, yes it's only separated at the front so clean it out, bond it and bolts should do the trick, many thanks.

Digging out a bit of old repair from one bilge keel last night I discovered a split caused by the metal inners rusting and expanding, luckily it was only a 2" split and only had to drill a bit of rust out, used an acid rust converter and Dinitrol cavity sealant followed by filler - It won't stop the problem but will be OK for a couple of seasons. In hindsight I wondered if an acid rust converter was good for the GRP but it will all have to be sorted anyway eventually, gets to the point in all this when you just have to get on with things, otherwise it will never get on the water.

I used International Watertite for this which is an Epoxy Resin, it might also work for the plywood split - Think that's what you are suggesting anyway (some of you! You go around in circles a bit when you get different advice, like varnish versus oil etc I suppose!) Have used it to fill other small wood areas and coloured it brown with a pen when dry and varnish on top.
 
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Watertite is a fine filler, not an adhesive. If the split in the keel is more than a hairline crack then best to grind it back and repair with glass cloth and epoxy. If you are going to be doing your own maintenance well worth going on the Wessex Resins site for guidance on what you can do with epoxies and investing in a basic repair kit with resins, cloths and fillers. Very versatile material which will save you a lot of trouble in the future. Many other suppliers of the material but West has probably the best range and is readily available.
 
dylanwinter said:
from the wooden boat builders forum

they swear at it rather than by it

http://forum.woodenboat.com/showthread.php?143008-Water-Proof-Gorilla-Glue&highlight=gorilla

guaranteed to fail
Click to expand...

There's a tool shop in Preston, a proper one where everything is 5% of the price in Homebase, with blokes that actually know about their trade, and they sell a glue from Wudcare.

Oh, this stuff actually http://www.wudcare.co.uk/fastgrab.htm
Even says on the tub that it's happy in seawater.

It's absolutely brilliant. I use it for all wood glueing. Needs to be clamped well, but it's as strong as you like.
 
Yes, thats a polyurethane glue similar to Balcotan which used to be the market leader. Many other brands now available. Originally developed for gluing together cheap Eastern Europe shoes! Only downsides are that it is messy if you get it on your hands and is not structurally strong as a gap filler unlike epoxy.
 
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