Filling voids / inclusions with Poly or Laquer

[Darin Hornsby]

Does anyone have successful experience filling in small voids (i.e. 1/8 wide by 1/8 deep by 1/2 long) with Poly or Laquer? The wood is Claro Walnut Burl. CA has been an utter failure. It takes forever to dry and ends up getting soaked up into the wood. I do not want to use epoxy with coffee grinds. I want it to be clear as I think voids like this add tons of character. When I mix my 2 part epoxy, it gets a little 'bubbly' so I don't want to try that straight. Would just Laquer or Poly work? thanks!

[David T gray]

buy the accelerator for ca glue

[Darin Hornsby]

I read another thread where the accelerator only dries the top of the CA, causing a whole other problem. CA and I aren't getting along right now....

[Tim Thiebaut]

Darin I have no experience with this at all as I am fairly new to turning and learning alot everyday. But after reading your thread I just had an idea pop into my head and thought I would throw it out here, not sure if this will work or not so maybe someone with some experience will give an opinion, but I know a lot of pen turners make their own pen blanks with a poly resin that you can get at craft stores....if you mixed the resin up and left it clear you could maybe use this to fill the voids and it would still let the woods natural character show through. As I said this is just a thought, if you do try this please let us know how it works out, Tim

[Cecil Walborn]

I have used 2 part epoxy a lot. That is the only one I use to fill voids and cracks in wood. I work with cracked wood a lot. I fill the epoxy with a blue metal flake or a crushed stone a lot. I have also used it just clear and was told in looks like wood resins in the wood. I just kind of wonder if you maybe whipping the parts of epoxy when mixing thous causing the bubbles. I have never had bubbles in my use of epoxies. I mixing them slowly so maybe that is why I do not get bubbles. I use Systems Three 5 minute epoxy the most.

[David E Keller]

I think epoxy is probably your best bet if you want to fill the void(s). Just a thought... If you like the way the voids look, why fill them at all? They'll have just as much character without filling IMHO. I hope you'll post a finished photo when you get it the way you want it.

[Michael James]

I read another thread where the accelerator only dries the top of the CA, causing a whole other problem. CA and I aren't getting along right now....

try layering thinner applications / accelerator if this is the problem. Just a thought...........

[Les Elm]

When finishing I save the sanding dust and mix it with the MINWAX Poly to make a slurry to fill porous wood, inclusions or cracks on my wooden pen blanks.

When using Med CA, I apply enough coats to completely fill any pores or inclusions, turn down the hardened CA on the lathe to smooth out and check to make sure everything is filled before doing any sanding to avoid getting white sanding dust into any pores or inclusions.
I never use accelerator or BLO with CA as it causes too make problems for me.

Works great for me!

Les

[Darin Hornsby]

Everyone, thank you for your help! I decided to go with the Epoxy route. It013.jpg went OK-ish. I used Loctite epoxy (maybe that's the issue?). You have to very gently and slowly mix it, otherwise, it gets cloude/bubbly quick.017.jpg I got a little bit of clear and little but of cloudy. It's good enough, but not the perfection I was looking for. I'm still thinking of trying021.jpg poly and/or lacquer. I should test that and get back to the board on results.

Attached is the handle I did for my brother's expresso maker. 030.jpg

[Cathy Schaewe]

Just out of curiosity, how warm is your shop? I've had distinctly different results with the same epoxy, depending on shop temp. If it's unusually cold down there (less than 60, at a guess), the epoxy tends to be cloudy, whereas above 65, it's clear.

[Wally Dickerman]

When filling cracks or voids the last thing that you want is to have it look like a patch, which sawdust does. The most natural look is to use coffee grounds. First, to avoid having the surrounding wood stained from CA glue, cover the surface with a paste wax or a finishing oil. I put some med. CA in the void, followed by coffee grounds. Rub then in, poke them in adding CA as you go. Dental tools are the best. Ask your dentist for some used tools. I got a half dozen that way, some bent.(that's scary). After you've built up the coffee ground CA mix, let it dry without using accelerator.

Maybe you get a better look by using premium Starbucks grounds

[Prashun Patel]

Not sure why you're getting bubbles in the epoxy. It will be transparent, but some dry amber. Perhaps yr mixing it too much. If you use a slower setting epoxy, the bubbles will also have time to -um- "bubble" up to the surface and pop b4 drying.

Filling with any kind of varnish is tricky because it will shrink as it cures. Lacquer - like shellac - also doesn't like to be built thick; I think yr just asking for drying problems with any of these solutions.

If the inclusion is large enough where the clarity of the void is an issue then personally, I'm with David: might look better to leave it alone and to seal the inside so it at least appears finished.

[Edward Bartimmo]

The trick with CA is that sometimes it works and sometimes it doesn't. CA reacts with moisture. If it is a dry piece of wood with a large enough void it is possible to get the surface to harden while the CA in the middle only partially solidifies into something similar to silicon calking. If it is a small crack you can use CA, but you might consider doing it in steps and letting it dry between layers. Using accelerator can speed up the process, but it can also create bubbles or white crusty edge. THis is especially true when using thin CA and Accelerant....it cures so fast it creates white crystals.

Epoxy can be nice an clear... The longer the curing period, the more time the bubles will have to migrate out of the epoxy while it is setting up. Another solution is to use a butane lighter and just flash it across the surface of the Epoxy. THe carbon dioxide from the combustion (flame) draws the bubble to the surface. The challenge is not to hold the flame to close or to long on the workpiece. You don't want to burn the wood and the warmer the Epoxy mixture is the more fluid it becomes and will spread out. Yes, Epoxy is exothermic reaction and at warmer temperatures it cures better, but this also means that the solution in thinner (less viscous) and tends to run. However in a small quantity in an isolated location, such as a crack or void, this shouldn't be so much a worry.

Whether you are using CA or Epoxy you are going to have an issue of the wood underneath being shielded from any finish you apply to the workpiece. I thing that it is more noticable with CA just because CA tends to be thinner than Epoxy so it moves around a bit more and gets absorbed by more surface area. Epoxy is more viscous and doesn't move around as much resulting in smaller absorbtion pattern. In either case if you know what finish you are going to use, you can apply some to the area prior to using the CA or Epoxy....presto the wood underneath will match rest of finished work piece. The only issue is a couple of extra steps and time to permit finish to dry before applying CA / Epoxy.

I have moved to planning ahead on what finish I will use before I start turning a challenging piece (voids, cracks, punky). At the very least I will plan to use an oil to highlight the wood, which I can apply in targeted locations as I turn in order to use CA or Epoxy to shore up trouble spots. The ultimate tradeoff is having the time to let everything dry, setup, and cure.

Hope this helps.

[Darin Hornsby]

Ah ha! Yes, this weekend it was cold. Thanks!

[Scott Crumpton]

It sounds to me like you should be using a polyester casting resin. These resins are thin, clear, and colorless. Bubbles will quickly float to the top. You would need to build a damn around your void, fill the area with resin and allow it to cure, then turn away the excess. I suggest checking out the Douglas and Sturgess site for resins, instructions, fillers and coloring agents. I've used some of their materials, but otherwise have no interest in the company.

---Scott.