Delamination

[Paul H (admin)]

I'm getting MilliBee ready for the mighty Thames Raid (will miss you CDubs).

The curved hatch roof used a piece of 6mm ply lying around; I used decking stain to see how well it worked.

The left side took a hammering from the anchor chain, which I pulled in from the cockpit to avoid going forward. There is now some delamination along about 20% the end grain . Yes I know it should be sealed but the delamination is up to 20mm deep; most likely water entered from the top as it drained away from the curved roof.

I sanded a shallow angle on the ply veneer because the edge was a mess, then gave it a coat of epoxy. Here is the result:



The veneer is reasonable stiff and springy because of the epoxy, but you can see a Stanley knife fits in easily. I could open the veneer carefully and drizzle in some thin epoxy, then clamp it.

I'm interested to know how everyone would fix this problem?

Thanks,
Paul

[Chris Waite]

Paulie

Take it off and stand the crack side up, to make the best use of gravity

But the answer is

"Yes!"

CW

[inwe]

Paul.
If you try to re-seal it with epoxy, split it up as far as possible and as Chris says turn it up so that gravity has a good chance and get a VERY thin epoxy such as the newish mass epoxy and pour in; or make a new one! That way you can be sure of the joint.

Richard

[Jeremy]

As above, but warm it up gently with a hot air gun, as that will make the epoxy a LOT thinner, and it will end up almost like water.  Don't over do it though, as the added heat will also make the epoxy cure more quickly.

You could try sticking some bits of lollipop stick in the split to hold it open, warm the ply up, then drip the epoxy in, then removed the sticks and let the gap close up, which will squeeze out any excess resin.  All un-thickened epoxies go very thin when heated, so I'd use whatever you have already.

[Paul H (admin)]

All,
 
Many thanks for the feedback. Regarding heat guns, I have secured prime place for that giant heat gun in the sky :



I mixed up epoxy using Mass thin resin, that I bought for glassing plywood as it spreads easily. Approx 30ml was carefully drizzled in. The secret is to be patient and apply the epoxy every few minutes. A careful prod worked out the air bubbles, so that more epoxy could be applied.

Packing tape guns are incredibly useful. One 'bump' had opened too far, the tape gun held the bump flush within 2 seconds.

The tape gun has been used to hold matching pieces of wood together; I think it will help to hold down decking ply. A good tape gun can be used single handed with practice.

This is the quality one I bought from Amazon (http://amzn.eu/d8WGlB9) and it works well. Avoid the cheaper plastic framed models, as they flex too much.



-Paul