I need to come up with some way to attach a leash to a varnished balsa/redwood board. This board will not be glassed – just varnish. I don’t want any plastic showing on the board either. Here are my scattered thoughts on how to accomplish this task.
Scenario 1: Create a leash loop using roving and a couple of football shaped patches. I’m afraid that this might look strange though. The patches will probably be very noticeable in contrast to the varnished surface around them.
Scenario 2: Create a leash loop using roving, but attached to a one inch dowel using epoxy. Drill a one inch wide hole into the top of the board and insert the dowel with the leash loop. Here is a terrible free hand drawing of my idea:
drill 2 holes through the board. on the bottom, make the holes bigger. run one piece of nylon braid in a U shape through the holes, tie knots in the ends protruding from the bottom. pull the rope toward the top so the knots are hidden in the larger bottom holes. Fill or cover the bottom holes. fill the holes from the top to the top surface
I’ve never done this but now I quite like this idea. I was thinking on how you could have minimal non wood visible. If you could match the colour of your wood it’d be very unobtrusive.
If you did this I’d use a SS bolt/rod so it didn’t corrode.
Now i’ve thought some more if you sunk it right through and drilled a small hole in the bottom disk you’d be able to replace the cord if it broke.
Or you could make a more conventional fin cup along the same lines.
The board’s looking beautiful, I’ll look forward to hearing about the test ride however you put a leash on it.
What if you just take an old glass fin, cut a piece of it out about 2 inches by 3 inches, make one end of the 3 inch long part rounded and then make the sides and the other end of the 3 inche side flat. route out a slot in the board and place the piece of glass into the hole leaving the rounded end standing up about a inch or so. Glass this into the board using chopped glass and resin, once it dries just drill out a hole in the part that is standing up off the board, it should look cool.
Thanks for all the great ideas everyone. I’m not sure which one I’ll end up with. They all sound good to me. I’ll probably experiment with a few different models before gluing it into the board.
Squid Inks design is appealing because it doesn’t require any epoxy. I’m wondering if the wood might start to rot in the hole though.
If I do go with a fiberglass/epoxy scenario, can I use ding repair epoxy? I’d rather not have to spend the money to by a large container.
You didn’t explain, but I’ll assume a balsa board with redwood stringers? Or redwood planks alongside balsa? I would personally consider the following simple method:
Get a hardwood 3/4"dowl x1" long (+/-) (preferably mahogany to match the redwood in which it will be drilled and glued) and drill a 3/16" (or so) hole through its length. The diameter of the hole should just be enough to run the two ends of a loop of nylon stringing rope through the hole. Force or push the rope through with an awl or small drill bit. You will tie a knot at one end (the bottom of the dowl) with a small loop of rope coming out the top end of the dowl. Squeeze in a small amount of epoxy in the top of the hole where the loop exits the dowl in order to water seal the hole.
Drill a 3/4" hole x 1" deep into the redwood at the tail end of your board and insert the dowl with titebond yellow glue or epoxy. When finished, the only thing you will see is a loop of rope coming out the top of one of your stringers. Since the glue is stronger than your wood you will have no problems. Varnish the top of the dowl with your board to seal it.
I created a test plug using a one inch diameter hardwood dowel cut off at about on inch. I don’t know exactly what type of wood it is. I drilled two 3/8" holes all the way through. I then flipped it over and drilled one big hole going about 1/4" deep.
Here’s the view from the top.
My picture of the bottom hole turned out blurry, so it isn’t shown.
I didn’t have any rope or roving, so I individually picked about 50 strands out of a piece of 4oz cloth. Here they are hanging from a piece of tape.
I then looped the strands through the holes in my plug. I tried knotting the ends individually, but the knots kept slipping through the holes. I ended up just tying the ends together with a square knot. A piece of rolled up painters tape gave it some supporting arc. Here it is ready for resin.
Here it is after the first coat of resin (Polyester Resin).
I let it dry for a couple of days. Tonight I went down and sanded off all the stringy threads, and roughed up the surface for the next coat. Here is a side view of the loop after the second coat was applied.
Here it is from the top.
My plan is to use a Forcner bit to drill a hole in the board. I’ll then use Titebond III waterproof glue to hold it in.
Should I wait until after varnishing to drill the hole and insert the plug? Can you varnish over polyester resin?
Note: Please tell me if you don’t think this will work, or if you think it will look retarded. It didn’t take too long to build, and I haven’t installed it yet.
I’ve done similar in boatbuilding and it works fine…
Make a “horseshoe” of glass or carbon rovings and epoxy. Leave a length of the ends un-resined. Sand the ends of the horseshoe.Drill oversized holes in the board. Support horseshoe in place with resin just going into hole and the fibres pushed well down. Use a syringe to fill holes with epoxy thickened with colloidal silica.
Its actually pretty important to prime the holes with unthickened epoxy first, it allows the wood to adsorb the resin and make a really good bond. I’ve done tests on this sort of thing and found that it took more than 500kg to pull the plug out, on some woods we got to 1500kg!
I just reccommend epoxy because it is a better glue that polyester. You can varnish over it no problem. You could do it in 2 applications, fill with thickened resin to 2mm below the wood surface and allow to part cure, then add more resin thickened with wood dust to give a better colour match.
Its actually pretty important to prime the holes with unthickened epoxy first, it allows the wood to adsorb the resin and make a really good bond.
Good point.
I neglected to provide the details of my process. My first coat of resin was thinned out with ascetone. This allowed the resin to flow down into the 3/8" holes, and wet the square knot at the bottom. I waited about 30 minutes, until it had hardened enough, and then removed the roll of blue tape supporting the loop. Next I mixed up a batch of resin and thickened it with some fiberglass clippings. I dabbed this mixture on the top of the loop to give it some thickness. I let it dry for another 30 minutes and removed the rest of the blue tape. After drying for a couple of days, I sanded it, and brushed it with another coat of regular sanding resin.
Note: I used Polyester resin because I already had that available, and didn’t want to buy anything new. I agree that epoxy would have been better to use. It feels pretty solid now. I think that it will be pretty strong.
