Filling bug holes with epoxy resin

Harveee | Posted in General Discussion on July 6, 2021 05:08pm

Hi, I’m new to all of this… but at least I know i’m probably doing it wrong.
I have a bunch of Claro walnut with cracks, voids, and bug holes that appear to run extensively throughout the slabs. I’ve tried pouring crystal clear epoxy resin tinted blue to fill them. That works with the cracks and voids, might take 3 pours to get level and fill completely. BUT many of the bug holes mostly won’t even take the resin and are left empty. I want everything filled with clear blue. I’ve litterally been learning the process for days and days and just sanded down a few boards and found that the epoxy resin only superficially covers many of the holes. I poured some black cyanoacrylic in a few today (figured a few small black dots might look cool too), but it’s eating a LOT of expensive glue. I would like to fill as completely as possible for strength and longevity related to the possibility there are unseen tunnels and voids throughout. Any advice, words of wisdom , help, ideas would be greatly appreciated. I figure I should just keep at it and do whatever feels like I should to move forward. The wood is gorgeous, and some will be used as a waterfall counter top and some will go as inside window sills, and some will be left over. I’d rather not leave exposed and open. Maybe I should get a thiner epoxy resin, but the stuff I’m using is pretty thin to start with, having a hard time not having my tape blow out and/ leak out ( that took a bunch of different tapes and suggestions that weren’t good. FLash release and tyvek tape don’t even stick to wood, Duck tape sucks too, best so far is green frog masking tape with multiple staggered layers). I’m wasting a lot of epoxy resin and tape so far. Thanks for your time

Replies

_mj_ | Jul 06, 2021 05:51pm | #1
If you plan to cut it up for your projects, wait to fill until it is rough sized. You could also push in some bits of sponge to backstop your pours.

Harveee | Jul 06, 2021 06:33pm | #3
Thanks MJ, I have it 2-4" longer than I need so I don't have to fill and sand more than I have too. I've used some caulking with a little luck, but I don't like that process because the caulk does shrink a tiny bit and still needs taping. As for sponge, I feel like it would create more bubbles and likely add more pours, but something to consider. Thanks for the ideas

_mj_ | Jul 06, 2021 06:50pm | #5
soak the sponge in epoxy before you push it in... no bubbles.

john_c2 | Jul 06, 2021 05:52pm | #2
There is an epoxy product called Rotfix that might work better. It's very thin, and might absorb better, but I'm just guessing.

Harveee | Jul 06, 2021 06:34pm | #4
Thanks John, I'll check it out right now.

gulfstar | Jul 06, 2021 09:15pm | #6
Use a heat gun to thin your epoxy, both before and after pouring. I have done it on ants nests in wood turning for the most spectacular results.
hoovermd | Jul 06, 2021 11:28pm | #7
So, I use the West 105 with the 206 slow hardener.
My complaint is that this mix is so thin I have to tape off every crack lest the epoxy pee thru the cracks.
ysu65 | Jul 07, 2021 06:29am | #8
Interesting problem. I have used epoxy colored with graphite to fill holes and cracks in cherry, oak, and black locust. Never had a problem with filling holes but I only had to fill several holes in a part. I wonder if a vacuum system would enhance the fill but that is a pretty expensive solution for an occasional problem. I used a turquoise epoxy fill normally used by bowl turners on a quilted maple table top that had a lot of cracks around a knot hole, worked out fine.

Drifting off the original topic, I just filled a large worm hole in a black locust board with a easy to carve mahogany insert, should have used walnut which would have blended in better but this was the first time I used this technique instead of a butterfly. Came out fine.
DRBWWing | Jul 07, 2021 10:01am | #9
Is the wood kiln dried? If not, are the bugs active? Only time will tell.

Personal experience, I've had PPB holes appear in cabinet doors 2 1/2 years after they were built.

The lumber came from sawmill that had a kiln, and I assumed it was kiln dried, later found out the only do that on demand.
kenbrechen | Jul 07, 2021 01:38pm | #10
You don't say where the epoxy is running to. But why not stuff the hole short of the surface with wood filler or "Plastic Wood." The stuff doesn't shrink and you'd be using a lot less expensive epoxy. However, you probably don't want to attempt this until you're close to a final sanding lest you strip off the epoxy.