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Bill Bell
06-13-2022, 3:30 PM
I know this topic has come up before in various ways, but I'm still confused about the best way of filling cracks. Whenever I try to use resin or CA glue to fill a crack it runs all over the workpiece, creating a total mess. I feel like I need something more viscous or gel-like that would stay in place as it cures. The other issue I have is how to force the filler into the crack so it has some degree of structural integrity. Even when I'm using a fairly liquid resin or glue it tends to just sit on top of the wood (and then run all over) rather than getting into the crack.
At present I am faced with filling the crack on a walnut bowl that I turned recently. This was turned to final dimensions (about 3/8 in.) so I'm not especially worried about the structural integrity of the piece as it won't be subjected to a subsequent turning. The crack is about 1/16 wide and around 3 inches long. (See attached pic.) Any suggestions for what to use? And about my questions more generally?
Thanks

Paul Williams
06-13-2022, 9:00 PM
To protect the work piece, I tend to give it a light coat of shellac before filling cracks. Probably doesn't help the glue bond, but I have not had any trouble with the method. For that crack I would use either tinted epoxy, or coffee grounds packed into the crack and saturated with CA glue. I am sure you will get many possible fixes, and most will work.

Paul Williams
06-13-2022, 9:16 PM
Bill, this isn't required for your bowl, but if it is too bad you can always cut it apart and insert another piece of wood. This was a bowl that dried so warped that it could not be turned the second time. I think I have posted it before. It happened several years ago.
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John Kananis
06-14-2022, 8:32 AM
Pretty new to turning but as far as penetrating deep with ca glue... use a very thin ca glue first and apply a little at a time into the crack. Then use the more viscous ca and it will follow the thin deeper into the piece than if you would have used the thick stuff off the bat.

Prashun Patel
06-14-2022, 8:40 AM
Don't glue for structural integrity. Glue for aesthetics. A bowl is about the hardest kind of wood piece to dry. The grain orientation and varying thickness of the blank create all kinds of stresses. The bowl will do what it wants to do - even after it's stabilized.

Mask the best you can.
Slow setting epoxy is viscous enough that the run is minimal. Drop it in with a toothpick. An epoxy like Sys 3 T88 has a 40 min open time so you have plenty of time to fill.

After it's dried, scrape, sand, or turn off the excess. Epoxy is wonderful in that it doesn't penetrate the surrounding wood that deeply and can be completely sanded off the unwanted areas. It also takes a finish just fine.

Richard Coers
06-14-2022, 11:08 AM
I'm an old school turner, been at it 37 years this fall. I don't turn cracked wood for my physical well being, and if it cracks anywhere in the process, it is reserved for smoking pork loin. I know there is a broad acceptance for cracks these days, but it's just not for me. I don't see cracked wood in the AAW Journal, so I'm fine with my decision. And you don't have to worry about CA staining, epoxy running, and spending big money for resins. I do repair knots, and that is done with epoxy and used coffee grounds. It has a subtle look and mimics the original knot.

Dave Fritz
06-15-2022, 8:54 AM
I put one of these under anything I'm gluing, esp. on the lathe ways. https://www.amazon.com/All-Absorb-Count-Training-23-5-Inch-White/dp/B00ODRO7W8/ref=sr_1_7?keywords=pet+pads+for+dogs&qid=1655297266&rdc=1&sr=8-7 One box will probably be a lifetime supply.

Jeffrey J Smith
06-16-2022, 7:57 PM
I use tinted (usually black) West System epoxy. Very slow setting, low viscosity penetrates well. A hot melt glue gun makes a nice dam around the opening. Pour to full, wait a bit, refill as necessary. Still makes a mess. Plastic sheeting is your friend.

tom lucas
06-16-2022, 9:12 PM
I put one of these under anything I'm gluing, esp. on the lathe ways. https://www.amazon.com/All-Absorb-Count-Training-23-5-Inch-White/dp/B00ODRO7W8/ref=sr_1_7?keywords=pet+pads+for+dogs&qid=1655297266&rdc=1&sr=8-7 One box will probably be a lifetime supply.

I made a little table from plywood with runners that lock it snug across the bed ways. It covers and protects the bed ways nicely and gives me a table to work from. When I'm finished with a clear coat of whatever material, I wipe the rag on the table. Seals the table and dries the rag before deposal. I have another small piece of panel board that I sometimes use to protect the headstock face by just leaning it up there.

As far as how to fill, I'd use thin super glue followed by thick colored to match the wood. Coloring could be with saw dust or dye. But I think it's too wide for sawdust. I'd probably use something real dark here because you are not likely to make it invisible anyway.

Paul Williams
06-17-2022, 9:34 AM
I agree with Tom and others who have mentioned coloring the epoxy or glue that you choose to use. It is hard to hide cracks, so they are not noticeable. Considering a crack a feature and letting or making it stand out is better.