crack filler idea's

[Greg Bender]

I'm wanting to fill a black walnut crotch piece that is going south on me the closer I get to finishing. I would like to fill it with some black epoxy type with a glossy look. I've used two part epoxy but I've never tryed to color it. What is the recommended approach? Any particular product better than all the rest? Should I have some kind of finish already on it when I fill the cracks? Basically ,at what point in the turning should I be looking at filling the cracks?
Thanx for the help in advance,
Greg

[John Keeton]

You can tint epoxy with Transtint dye, though it will thin it a bit. You can also use universal tint from a paint store - it doesn't take much. On walnut, I have used coffee grounds and Titebond, as well, with good success. It is nearly black when finished. Nearly any of the fillers will take finish and subsequently, a gloss. You don't really need the filler to be glossy.

I would suggest at least a coat of shellac prior to filling the cracks as some of the glues and/or pigments will bleed into the surrounding wood.

[Steve Schlumpf]

Greg - you can buy black epoxy or add black wood dust (Ebony, Blackwood, etc) to the mix shortly before placing it in the cracks. I use epoxy sometimes but mostly use CA glue. I found the best way to keep the glue or epoxy from staining the wood is to apply the finish of your choice first. I use poly most of the time and usually put on 3 or 4 coats - then glue up the cracks. Also, depending on the look you are after, once you have a finish built up a bit you can also sand the area using some fresh finish as a lube. Basically - create a slurry and fill in the cracks that way.

[Roger Chandler]

Very timely thread for me Greg, with the black walnut platter rough-out I just posted last evening.............very good answers from John and Steve............thank you much gentlemen..........this advice will do me good in filling that crack/void in the base of that platter...........if you notice on the pic there is a small void in the face of the platter as well, and I suspect it will go all the way to the base and is part of that crack...........

..........this should help me a lot in making a good repair..........thanks again!

[Neil Bosdet]

When I've needed to fill voids, I use epoxy and mix in the dust from the same wood. Get some walnut dust from sanding a scrap and mix with a little epoxy and try it on a scrap piece to see if you like the results.

[Bob Wolfe]

Another option, you will need 2 part epoxy in bottles, not the syringe, black ink and alcohol

To make about 2 tablespoons of filler, add a few drops of black ink (stamp pad refill ink from your local office supply store) and a few drops of alcohol (rubbing or denatured, doesn't matter) to a about 1 tablespoon of 2-part epoxy resin and mix. You should have something in front of you that is very black and quite thin (maple syrup). If it is not, add just a few more drops more ink or alcohol as needed. Then add about a tablespoon of epoxy hardener. Mix and apply to your voids. It may take more than one coat and it is better to build it up in layers. You can keep adding more as it gets tacky, but wait a day or so until it is completely cured and hardened before you try to sand, scrape or cut to blend it with your surface.

I have used this a few times and got very good results. I got a filler that was hard, cut and sanded nicely, and was glossy.

[Larry Pickering]

Starbond makes a black CA, extra strong bond

[Pat Scott]

You didn't say how big of crack you want to fill. I've only used thin and medium CA glue, in my opinion these should only be used for small cracks-maybe up to 1/16". For anything larger than that I use epoxy. I've found if you use Walnut sawdust mixed with epoxy or CA glue, the result is a light brown patch, not black. I don't have any ebony sawdust so can't comment on it's use. I've used coffee grounds before, and it's more brown than black as well (maybe it depends on the type of coffee? French Roast vs Breakfast Blend? :)).

What I use is epoxy with some black Artist oil - the kind of oil that comes in a tube and is the consistency of toothpaste. Artists use it for oil painting and you can buy it at any craft store such as Michaels. I use 2-part epoxy that comes in separate tubes (not the syringe combo), applying just a bit of Artist oil to the resin (the clear epoxy). After mixing the oil with the resin, then I mix in the hardener. The reason for adding oil to the resin first is that the overall amount of epoxy could change, and you want to be sure to add an equal amount of hardener. If you're just filling a small crack or void it's not that big of deal and you can mix it however you want. A tube of Artist oil will last forever, you'd be surprised how little it takes to color the epoxy black. Another benefit of using artist oil is the overall consistency of epoxy doesn't change. Using sawdust or coffee grounds creates a thicker consistency that doesn't flow as well.

I use a small artist spatula to work the epoxy into the void trying to get rid of all air bubbles. The epoxy will slowly settle and fill the void/crack. Make a little mound of epoxy over the void so there is extra as it settles. Check it after 20-30 min and add a little more epoxy if needed. For this reason I use 24 hr epoxy, not the 5 min kind. The 5 min kind will set too fast and won't flow into all the nooks and crannies.

After the epoxy has dried overnight I'll sand the patched area off the lathe using my drill and sanding discs. Sand enough to get it close to the surface, you don't have to remove all of it if you don't want. Then you can put the piece on the lathe and continue turning it. If you uncover an air pocket or an area that the epoxy didn't fill in (or you didn't leave a big enough mound of extra while it cured), just mix a bit more and fill again. Epoxy will stick to itself and not pull out of the gap. I've found when using CA glue that if I try to fill an air pocket or void, most times the CA glue not stick and pulls right back out.

When to fill? When the piece is dry and just before you reach your final thickness.

Epoxy has the strength to fill larger cracks and voids. Artist oils come in all different colors. Here is a black epoxy filled crack in a Walnut platter.
228499

[Jim Burr]

You can use anything from espresso powder to metal oxide. Devcon makes black epoxy that I've used on several items. I would recommend that you pre-treat any area that could come in contact with the filler material. I'm using a lot of metal oxide and CA on a swap piece. Every area gets Tung oil finish, taped off and then filler applied. Lot of effort, but it beats sanding!

[Bernie Weishapl]

I use a drop or two of black transtint dye in epoxy.

[ted moore]

You can use anything from espresso powder to metal oxide. Devcon makes black epoxy that I've used on several items. I would recommend that you pre-treat any area that could come in contact with the filler material. I'm using a lot of metal oxide and CA on a swap piece. Every area gets Tung oil finish, taped off and then filler applied. Lot of effort, but it beats sanding!

I too have used the devcon black epoxy named "5 min steel" (I think because it has some steel filler in it).
I also have used toner from the copy machine mixed in with the resin then add hardner.
Both have worked well for me.

[Greg Bender]

I want to Thank everybody for all the info. I figured two part epoxy was the way to go so I could tint before dealing with the hardner.I guess I need to finish sanding and then it's off to the Big Box Store to find one of the above mentioned epoxys. I have transtint so I'll start there.

Roger,
your post is what made me decide to post the question.I'm glad it answered both of our issues.
Greg

[Dick Wilson]

Greg, I have mixed a number of things with epoxy to fill cracks, etc. You could use old coffee grounds. I have used artist chalk sticks (ground into a fine powder) You can get hundreds of different colors/hues.

[Bill Wyko]

I mix epoxy with a dye for coloring fiberglass gellcoat. It only takes a drop the size of a BB it's so concentrated. I used it on the vessel in the Beauty & the beast contest and just about anything that I dye. it's available in all sorts of colors too.

[Greg Bender]

Bill,
Where would that product be sold? Or is it available online?
While this thread is still moving I have to ask, what does the experienced turners think that the Moultries from Atlanta use to fill there 5 gallon buckets with Epoxy?I watched that PBS show awhile back and there finish and those epoxy filled bucket Blanks absolutely intrigued me.
Thanx again,
Greg

[Neil Bosdet]

Bill,
Where would that product be sold? Or is it available online?
While this thread is still moving I have to ask, what does the experienced turners think that the Moultries from Atlanta use to fill there 5 gallon buckets with Epoxy?I watched that PBS show awhile back and there finish and those epoxy filled bucket Blanks absolutely intrigued me.
Thanx again,
Greg

I'm with Greg. I watched the Moulthrop family episode on the PBS video and was really inspired. I love the epoxy in a bucket thing. I think the bucket was more like a 3 gallon but still, epoxy is very expensive (at least around here), so it will be quite an investment to try this out. Any of you know what type of 2 part product they're using?

Cheers,

Neil

[Scott Conners]

If strength is an issue in your application, watch what you put in the epoxy. Diluting with alcohol and/or ink can effect the cure and final strength quite a bit. What the composite guys use in aircraft to tint epoxy is powdered graphite. Any fine black powder will work well though, like charcoal or other carbon.

Neil - They are most likely using a polyester resin, which is much cheaper than an epoxy resin. It's the same type of stuff most pen blanks are cast from. try a Google search for "casting resin" or "poly resin". It can be bought black, or tinted like epoxy.

[Neil Bosdet]

Neil - They are most likely using a polyester resin, which is much cheaper than an epoxy resin. It's the same type of stuff most pen blanks are cast from. try a Google search for "casting resin" or "poly resin". It can be bought black, or tinted like epoxy.

Thanks. I'm looking into it.

[Greg Bender]

Neil,
Thanx for correcting my spelling snafu on the Moulthrop's and

Scott,
Thanx for the recommendation on the casting resin.I am also looking into finding some.
Greg

[Russell Neyman]

Stick Fast makes a flexible black CA glue that is extremely handy for cracks. When mixed with a little dark sawdust, it really looks like woodgrain, and because it has a degree of flexibility it stays put better than ordinary CA. About six bucks.

http://www.woodworkingshop.com/product/ca00011/?inMed=MSSTORE

[Jacob Reverb]

FWIW, I've successfully mixed epoxy with carbon black. (I used charred newspaper and some charcoal bits from the woodstove, rubbed/pushed through a window screen.)