Rebedding Question

[unbusted67]

I am re-bedding a bunch of deck hardware this winter and wondering about the best way to boor out the holes to fill them with epoxy. A lot of people recommend using an allen key or ice pick to get inside the fiberglass shell to dig out the coring. The problem is that with small holes you can't get the right angle or the hole is too small to fit anything like an allen key in there. Can I just drill out a hole a few bit sized larger than the screw size and fill that with epoxy? Or is it important to leave both layers of fiberglass intact and to dig out the coring from within?

[Rhapsody-NS27]

I was looking at the books (Calder or Casey) I have on repair for when that day comes and it looks like you can drill a whole larger than you need, if the core still looks intact (dry and solid), fill with epoxy then when it's set, drill the smaller size you need. But, if the core in the immediate area of the whole needs work, then y ou dig out the coring.
Of course, someone who knows more is likely to chime in soon too.

[minaret]

Originally Posted by unbusted67

I am re-bedding a bunch of deck hardware this winter and wondering about the best way to boor out the holes to fill them with epoxy. A lot of people recommend using an allen key or ice pick to get inside the fiberglass shell to dig out the coring. The problem is that with small holes you can't get the right angle or the hole is too small to fit anything like an allen key in there. Can I just drill out a hole a few bit sized larger than the screw size and fill that with epoxy? Or is it important to leave both layers of fiberglass intact and to dig out the coring from within?

Some people will recommend boring out a few sizes larger and filling and re-drilling. While this can be an acceptable approach for very small holes ( 3/8" or less) in some applications, I avoid it wherever possible. Maintaining both skins is a much better solution. Allen wrenches chucked into a drill are the usual poor mans technique, but have all of the problems you already mentioned as well as just not being very efficient. Personally, I often use router bits chucked into a cordless for this. But I work in a pro shop and so have a wide variety of router bits at hand. Still, if you have a number of holes to do in a given size, it can be a real time saver to go pick up the appropriate router bit. The many advantages to this include very high speed and efficiency, and the fact that it easily and safely removes all core down to bare glass. An allen wrench doesn't come close to doing that. If you have an extremely thin inner skin, as sometimes is the case, this can be the only method that will perfectly preserve it. Sometimes in that case I will use a dado bit with a pattern or flush trim bearing on it, it helps you get every last bit of core out down to the fragile bottom skin without damaging it. Obviously this only works in slightly larger holes. Use quality router bits with multiple flutes for this, a cheap single flute blade will want to stutter and be harder to control. The general rule of thumb is to route out as much material as the core is thick, ie for a 3/4" core use a 3/4" depth of cut router bit. Sometimes it's very helpful to start with a smaller bit and then move up.

[rognvald]

I have used a dremel attachment that is barrel shaped on the end with 360 degree blade-like spines that removes core material perfectly after drilling your holes or using the originals. You can find it at any store that sells Dremel supplies. It removes about 3/8" of the core material beyond the holes. Good luck and good sailing, Ron

[CharlesFCook]

Here is a good article...

Re-Bedding Deck Hardware Photo Gallery by Compass Marine at pbase.com

[mbianka]

Originally Posted by unbusted67

I am re-bedding a bunch of deck hardware this winter and wondering about the best way to boor out the holes to fill them with epoxy. A lot of people recommend using an allen key or ice pick to get inside the fiberglass shell to dig out the coring. The problem is that with small holes you can't get the right angle or the hole is too small to fit anything like an allen key in there. Can I just drill out a hole a few bit sized larger than the screw size and fill that with epoxy? Or is it important to leave both layers of fiberglass intact and to dig out the coring from within?

It's best to keep as much of the skin intact as you can. I used a technique I learned from Maine Sail aka Compass Marine Services. I used a Dremel Tool to take out the core without overdrilling the skins when I rebedded my hand rails last year. You can see what I did here:
THE BIANKA LOG BLOG: REBEDDING HANDRAILS: Part 3 Remounting the rails
There is also a link to the Compass Marine site in the post which is very informative on the process.

[Khagan1227]

If you have balsa core, the allen wrench works pretty well, if you have plywood core, I'd go with the dremel and a cutting wheel, but with small holes, this will not work.

Using a larger hole will allow you to use a more appropriate bit and still undercut the fiberglass for strength.

After the undercut (or backing washer/plate if going through the cabin top) is complete, use a plastic syringe to inject the epoxy into the hole. Using a syringe makes it more likely to completely fill the void and encapsulate any new wood exposed by this process.

[roverhi]

I use a dremel tool with a cutting bit, believe it's the 199 Dremel High Speed Cutter [DRE199] | Tools - A Main Hobbies or one that looks like this. For smaller holes I cut in at an angle till I can get the cutter horizontal and rout out the core. By going in at an angle, don't cut up much of the FRP top layer of the deck.

I tried allen keys in a dremel but the dremel just didn't have the torgue to swing it unless I ground the Allen key down so it was almost too small. The 199 Dremel bit worked so much better especially at cleaning out all the core material. If you used a drill, an allen key will work better but chatters pretty badly and can bust the Allen key.

Once I've gotten the core cleaned out, use a syringe to squirt in resin and then suck it out. Figure the straight resin will soak into everything and insure a good bond. After I've sucked out the resin, add filler to about peanut butter consistency, refill the syringe with it and inject that in the deck. Leave it a little proud and sand down after it kicks.

I also chamfer the whole with a counter sink bit in my screw gun. That makes for a much better bond at the surface for the expoxy. Putting filler in a straight drilled hole sometimes cracks between the filler and deck which I assume lets water into the core.

[SKI]

A woodruff keyseat cutter would work very nice. They have a thin face then the shank is relieved to a smaller diameter. they come in a variety of sizes from MSC metalworking or Mcmaster-carr. probably similar to the router bits mantioned above. They usually have 6-10 flutes so they won't chatter around much in a hand drill.