Screwing into end grain ply

[alec]

Last season I very easily (for me) made two ply cockpit locker lids.

I had to screw into the end grain for the locker catches.

They now will not hold the screws and the area has gone a bit mushy.

Where have I gone wrong ?

Thanks in advance.

 

[Guest]

Basically because you cannot successfully use end grain of ply to screw into. It has no "bite" or "body" to bite into.

A simple solution is the wood dowel trick. You line up where screws will be placed ... then drill vertically down through the ply suitable holes to glue in wood dowels. Once glue has set ... you then drill suitable pilot holes for your screws that then screw in and bite into the dowels ... anchoring your screws far better. The visible ends of the dowels cannot be hidden that well - so stain and don't try to hide them - make them actually visible and nicely finished off.

You can if you are clever ... actually lift the top veneer and insert the dowels ... glueing the veneer back to hide them ... but needs extreme care to get it right.

 

[MoodySabre]

Why didn't you use a hasp type fitting with a hinge so that you could have screwed into the underneath of the lid? Or glued and pinned a solid piece of wood along the edge into which a screw could be fixed?

I'm good at closing the door after the horse has bolted. /forums/images/graemlins/wink.gif

 

[FAITIRA]

Just done the same job, I used marine ply, price horrendous, in France anyway, but, turned out well. I fixed the hasp catches under the lids, it will never be a success into the end grain. Try plugging the holes you have made and redoing the catches into the underside of the lid. It,s a bummer when it dosn,t work out! I hope plugging the holes saves the ply.

 

[oldsaltoz]

You could cut the soggy bit off, treat the exposed edge with an epoxy and glue a hard wood strip the same thickness as the ply, use micro fibres with the resin and the timber will break before the glued joint.

Have made some nice tops this way but with hard wood on all 4 sides and rounded corners.

Hope this helps.

Avagoodweekend......

 

[kds]

You can solve this by raking out the mushy stuff - getting the ply really dry and then run in a thin, liquid epoxy (slow cure) and rotate so that it coats and soaks into the surrounding ply, but not filling up the hole. Then make up a much thicker epoxy mix, using fine sawdust or that white powder filling material (like cotton fibres ?) and run in to fill up the holes, before first layer has gone off. Then you can drill into and put screws where you like.
Not the classiest way - but VERY strong and who will notice ?
Ken

 

[tcm]

Re-engineering solution

If the ply has gone mushy then the wood is getting wet, and if it's gotten wet in the end grain then ply is No Good. You can repair as much as you like, but the ply is on its way out and was the wrong choice of material. Incidentally, the same applies to shitey uk motorways with lorry-wheel grooves innem btw - they can try fixing them as much as they like but in fact they are inherently crappo and also need re-enginnering.

So, in your case you need to rip off the cockpit locker lids and use some other material. Admit it to yoursel - the plywood idea was rubbish. instead of ply, you can make a slab of teak from strips, or use plastic, or get a grp locker made, or get rid of the cockpit lockers altogether, or swap the boat. All these will cure the problem.

In the case of the uk motorways, the whole lot needs ripping up, dig down about 2.5 metres and put in massive reinforced steel cages, shuttering and concrete (using the aggregate material already there, so don't need billions of lorries or massive landfill, just some steel and steelfixers), then a roll down a simple wearing layer of tarmac, like on the continent where their older motorways remain smooth despite having heavier lorries going faster onnem.

 

[Graham_Wright]

I have addressed the same problem and ending up taking "special" standard butt hinges delivered undrilled and silver soldering returns on them so that I could screw into the back of the locker lid. It was a hell of a job to get right and there is obviously an opportunity for a manufacturer to come up with a solution.