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**s/v Jedi** · 30-11-2009, 10:44

Quote:

Originally Posted by delmarrey

I'm not too worried about the crush. I use thick SS backing plates. My main obvective is to seal the core from water intrusion.

The risk of crushing is on the top-layer of glass, not the bottom so the backing plate doesn't help for that. The reason is that the injected epoxy will travel down by gravity and the possible air inclusion (voids) are at the top, under the upper layer of glass. For clutches, cleats and winches, you load the fasteners in shear which leads to increased risk of crushing. It's also very important to tighten the bolts to the recommend torque for shear loading. This info can be found in tables and it's a percentage of the breaking strength.

Quote:

I'm not sure I like the holesaw idea with the flexing of the hull, especially under clutches, organizers and winches, I feel it may crack around the edges unless one were to put some layers of glass over it.

But that's the point: with the holesaw method, you don't have just a bond between plug and upper layer around the edges: you have a much bigger contact area at the underside of the upper layer of the deck. That bond is stronger than the deck itself so it will never crack there. Even if it would, there would still not be any water intrusion because the plug extends 1/4" under the upper layer all around the hole. Finally, the fastener is only in contact with the plug, not with the deck. This distributes the stress forces over a much larger area. All good.

ciao!
Nick.

FraidNot · 30-11-2009, 12:35

How do you use the Allen Wrench?
By hand or attached to low speed drill?

delmarrey · 30-11-2009, 13:50

Just like the picture above. You cut off about half of the short arm with an abrasive wheel and chuck up on the long end only long enough to reach the bottom side of the hole.

You feed it in sideways to get it in the hole, straighten up the drill motor and spin away. Then just work it around until the allen can touch the edge of the hole all the way around.
Withdaw it out sideways and vacuum/pick out the particals and go in for another round, or two.

If there's any resin it may bend and/or catch but usually breaks loose. If not just make it part of the fill material.

Just try to keep as much of the air bubbles out as you can.

Later this evening I'll do a video and post it on youtube.

unbusted67 · 30-11-2009, 20:06

Quote:

Originally Posted by delmarrey

Later this evening I'll do a video and post it on youtube.

Please do, I am only ever about %85 sure I know what anyone is talking about on here. I think most people learn best by example. That is why my girlfriend stairs at me blankly when I give her directions.

delmarrey · 01-12-2009, 05:06

This is a 8 minute clip that I quickly threw together. I cut out a lot of it to save time and space but ya'll should get the idea. One part that I cut was that I use large shallow mixing containers so to flatten out the mixture and allow the air bubbles to surface easily then tilt it sideways to suck up the mix with the syringe. I meant to get that in the video but I was too close up at the time. Oh well, here's the quickie.

I'm not saying this is the perfect method but I've probably done over 100 holes in my own boat and it's doing just fine. The ones on an high angle I've had to build a funnel effect around the hole using tape that rises above the hole and fill that with a thinner mix.