LumberJocks

Fixing a crack(s)

  • Advertise with us

« back to Woodturning forum

Forum topic by Mark posted 02-12-2016 01:05 AM 662 views 0 times favorited 11 replies Add to Favorites Watch
View Mark's profile

Mark

819 posts in 1434 days


02-12-2016 01:05 AM

Afternoon all. I was turning a vessel this afternoon and was darn near done, so just to break the monotony I had to catch an edge. So now I have 2 large and long cracks in the vessel. It has excellent grain and swirls so I want to save it. The plan is to accent the cracks with copper fillings. Should I: a) Mix up a batch (for each crack) of epoxy & fillings. Fill and clam? b) Glue and clamp the cracks with epoxy first. Then using a fine bit on the dermal, score the now sealed crack, add the fillings and cover with CA glue? In option “b” could I use CA glue instead of epoxy?
Thank you

-- Mark


11 replies so far

View Bob Collins's profile

Bob Collins

2313 posts in 3143 days


#1 posted 02-12-2016 01:30 AM

Mark, would you need filling in those thin cracks, if you can get a tight enough clamp on the vessel tightbond glue should do the trick, give it 24 hours to cure and do a fine sanding. If you are not happy then score the marks and fill with copper and CA glue. I can see why you want to save it, nice grain. Definitely a epoxy job for the side if you are going to fill. Lets see the results.

-- Bob C, Australia. I love sharing as long as it is not my tools

View Mark's profile

Mark

819 posts in 1434 days


#2 posted 02-12-2016 04:01 AM

Thanks for the advise Bob. No that big ass hole on the side stays. I’m going to have to chuck it up and re turn the top. The cracks won’t line up I don’t think. The insides down to 3/8” thick…could come down another 1/8. But I’m scared!!!

-- Mark

View JBrow's profile

JBrow

812 posts in 379 days


#3 posted 02-12-2016 04:15 AM

Mark,

It is a beautiful turning job and the wood is quite nice. I do not envy you the challenge of fixing these cracks.

If the vessel cracked because of stresses in the wood, re-gluing could lead to failure elsewhere since gluing could reintroduce the stresses. Even if the vessel hit the floor and the cracks appeared, it could still have resulted from internal stresses (I am not sure what “had to catch an edge” meant).

This is obviously a difficult piece to clamp. If you were to clamp, I suppose a band clamp at the widest point of the vessel might close the gap all along the vessel. Alternatively, a pair of semi-circular cauls could be used at the rim, but I am not sure to what effect on such a complex piece. Perhaps a little downward pressure from the small opening of the vessel would keep the upper (small mouth opening end) from opening up under clamping pressure.

One method I have used with some success to fix a straight crack on a flat surface is to first rip thin “filler” wedges (although accurately cut square filler strips also work). Then I made a through cut centered in the crack. Glue was applied to both sides of the wedge and inserted into the cut-open crack until snug – no clamps. In this case, multiple wedges may be required and perhaps would have to be introduced on both the inside and outside of the vessel. When the glue cures, the wedges are flushed-up with a chisel and sand paper.

However, in this case, I am not sure how well the wedge filling would work. The major and minor cracks have significant curves (not straight lines). Also, it is difficult to image that if successful with this fix even with the same wood as the turning, that it would not draw attention away from the beauty of the vessel to the fix. But I thought I would mention this method anyway.

Another idea similar to the “wedge” idea, since you are thinking of adding copper, would be to get thin copper, open the crack, maybe at the bandsaw, and epoxy the copper directly in place. The thin copper could make the bends required as a single continuous ribbon. The copper would have to be thin in order to flush it up but thick enough to bridge the gap. Flushing up the copper could be done probably using sandpaper. If the copper is cut in the profile of the turning before gluing in place, it would reduce the work of flushing up the cooper to the vessel. Also this method would require an epoxy that could accommodate the expansion and contraction of the copper. The significant advantage of this approach is that it keeps the Dremel out of your hands. If you are like me, accurately routing a space for the copper fill would be a challenge and I know if it were me behind the Dremel, I would just make bad matters worse.

I am not sure I helped any, but that is all I got. Good luck!

View Nubsnstubs's profile

Nubsnstubs

825 posts in 1189 days


#4 posted 02-12-2016 02:21 PM

You got your catch, so, did your vessel take flight? I ask because you didn’t say how it was held.

The suggestions you’ve gotten so far are good enough for me If that was my problem. I couldn’t add any new ones if I tried.

The wood is a keeper, so explore all the options before continuing… What wood is it? Looks a little like mesquite crotch wood, but could be any crotch wood…... ........... Jerry (in Tucson)

-- Jerry (in Tucson)

View Mark's profile

Mark

819 posts in 1434 days


#5 posted 02-12-2016 04:50 PM

Thanks for your detailed responce JB. It was basically a catch that did it. The piece was chucked up and did not fly when it bit. Ya glue up should be interesting.

Jerrry. I’m not sure what it is. Friend of a friend had had it for years. It was a large piece 8” sq x 25” L. I’m thinking’ Cherry

-- Mark

View Bob Collins's profile

Bob Collins

2313 posts in 3143 days


#6 posted 02-13-2016 02:57 AM

Mark, have a look at Ronald Campbell’s pages on LJ’s and see how he uses resin on his projects. His latest project points you to where he gets it. Might be handy in the future.

-- Bob C, Australia. I love sharing as long as it is not my tools

View BurlyBob's profile

BurlyBob

3644 posts in 1725 days


#7 posted 02-13-2016 03:20 AM

That had to be a real heartbreaker!

View Mark's profile

Mark

819 posts in 1434 days


#8 posted 02-13-2016 11:19 PM

Thanks for the link Bob. Mr. Campbell does some amazing work.

-- Mark

View Roger's profile

Roger

19855 posts in 2263 days


#9 posted 02-14-2016 04:43 PM

My guess would be to mix the filings with the epoxy. If you can get something in the crack to open it up ever so slightly without cracking it worse, then push/squeeze the mixture into the cracks the best you can, and gently clamp it. (gently) After they’re dry, sand em and see if you need any other filler. Just my thoughts

-- Roger from KY. Work/Play/Travel Safe. Keep your dust collector fed. Kentuk55@yahoo.com

View NJJoe's profile

NJJoe

7 posts in 598 days


#10 posted 02-15-2016 06:35 PM

Mark, an alterantive is to get some key dust from HD or Lowes, mix it with epoxy and than fill the crack. Under their key-cutting machines there will be a small dust collector which will have all the brass-colored dust you will ever need. Mixed with clear epoxy it gives a very nice textured metal look

View OSU55's profile

OSU55

1056 posts in 1449 days


#11 posted 02-15-2016 09:25 PM

Curious to learn more about the catch. Where were you turning on the piece, type of tool, etc.

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com