An odd observation.....filling a crack with Danish oil natural.....

[Odie]

I finished a small Goncalo Alves bowl yesterday, and didn't notice a small crack near the foot that went clear through from the outside wall, to the inside wall. Normally, I'd fill this crack with epoxy prior to finish sanding, but this one I didn't notice until after parting it from the wasteblock, and applying finish. (I'm using Watco Danish oil natural.)

I noticed that the light showing through the crack was smaller after the second application of Danish Oil, so I kept on applying the DO every few hours, until the crack was completely filled. It took at least five or seven applications before the crack was filled.

This is completely new to me, and am wondering if anyone else has ever done this......? I'm sure this is no replacement for a good glue or epoxy, but maybe it's good enough to save a bowl that would have certainly been a reject otherwise.

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[Charlie Knighton]

voids and cracks are eyecatchers......I much rather have the desired form than turning out the defect, course I do not demand perfection from myself to be satisfied.....but to reject a turning because of crack....not my critique to have perfection, almost like the word ..always....

 

[Bill Boehme]

The DO finish is hiding the crack (if I understand what you mean), but it definitely isn't repairing it. Epoxy and other strong bonding materials will ofter be enough to prevent future growth of the crack. Sometimes doing nothing also works. I suppose that you could just put it on a shelf until you feel satisfied that it will be OK without doing anything to repair the crack or determine that it needs to be tossed.

 

[Odie]

All very true, Charlie.....

We all would like to have perfect defect free wood all the time. As you say, the optimal way to deal with the inevitable cracks, is to choose a shape that eliminates the crack, or other defects entirely. Then again, I suppose one could always have defect free wood.....but, you'd have to give up on having the best figure and character of the wood to have it.

Anyway, the point of my post is to note that it is possible to fill a crack with Watco Danish Oil, if it came down to that. It's not the best way to do it, but it will work.

Later Charlie! 😀

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[Odie]

The DO finish is hiding the crack (if I understand what you mean), but it definitely isn't repairing it. Epoxy and other strong bonding materials will ofter be enough to prevent future growth of the crack. Sometimes doing nothing also works. I suppose that you could just put it on a shelf until you feel satisfied that it will be OK without doing anything to repair the crack or determine that it needs to be tossed.

Yep, not a repair, Bill.......just a fill in of the separation. If I had seen this crack prior to advancing beyond an easy epoxy fix, that would have been the best solution.....



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[Gretch Flo]

odie-are your bowls meant to be hand washed? will the cured hardened "sludge" disappear with use???? Gretch

 

[Odie]

odie-are your bowls meant to be hand washed? will the cured hardened "sludge" disappear with use???? Gretch

Beats me, Gretch......

Although most of my bowls are decorative, I do make some that are meant for food use.....don't believe I'd trust this to last if it were intended to be used for food, and therefore hand washed. This particular bowl is strictly a decorative bowl. I've never filled a crack with DO before, so this is new to me. I was hoping I'd find someone else who might have done this before, and knew something about it.....

The bowl is still yet to be Beall buffed and waxed, so there will be a certain amount of "sealing" over the top of the DO in the crack.......If this turns out to be a success, I'll add it to my "bag of tricks".......but still, as I said, the best way to handle it would have been to fill the crack with epoxy, as long as that's still an option. In this case , the epoxy option was not available, because the bowl needs to remain mounted to complete the epoxy repair.

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[john lucas]

Odie. Years ago I filled all small cracks with finish and sanding slurry. Used to work really well on small cracks and torn grain. Now I use thin CA and sandpaper to fill small defects. Torn grain can completely disappear and even some cracks. Others of course continue to show as repaired cracks.

 

[Gretch Flo]

Beats me, Gretch......

Although most of my bowls are decorative, I do make some that are meant for food use.....don't believe I'd trust this to last if it were intended to be used for food, and therefore hand washed. This particular bowl is strictly a decorative bowl. I've never filled a crack with DO before, so this is new to me. I was hoping I'd find someone else who might have done this before, and knew something about it.....

The bowl is still yet to be Beall buffed and waxed, so there will be a certain amount of "sealing" over the top of the DO in the crack.......If this turns out to be a success, I'll add it to my "bag of tricks".......but still, as I said, the best way to handle it would have been to fill the crack with epoxy, as long as that's still an option. In this case , the epoxy option was not available, because the bowl needs to remain mounted to complete the epoxy repair.

ooc

Why not put some superglue (I realize that with a long time that too may disappear as some have said), and litely sand in . The previous finish will prevent (at least with my Deft Danish oil-which is diff than Watco DO) the Sglue from absorbing into the surrounding wood (I think-this has been my experience). But the crack may be too filled with the now cured DO "sludge" . Gretch

 

[Odie]

Why not put some superglue (I realize that with a long time that too may disappear as some have said), and litely sand in . The previous finish will prevent (at least with my Deft Danish oil-which is diff than Watco DO) the Sglue from absorbing into the surrounding wood (I think-this has been my experience). But the crack may be too filled with the now cured DO "sludge" . Gretch

That sounds like a great idea.....thanks, Gretch......😀

Next time this particular circumstance comes up, I'm going to give it a try. I wonder if the DO and super glue can be mixed together......?

So, have you had success sanding the super glue to match the surrounding previously sanded surfaces? It's been awhile since I used any CA, and my experience with it was not good.....had too much trouble with the CA staining surfaces, and it was apparent there was an attempt to make a repair.

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[Bill Boehme]

If I see a hairline crack while turning or sanding, I will often hit the wood with a light coat of lacquer in the area around the crack and then apply thin CA to the crack. The lacquer keeps the CA from spreading out on the surface. The lacquer can then be turned or sanded away.

 

[Gretch Flo]

That sounds like a great idea.....thanks, Gretch......😀

Next time this particular circumstance comes up, I'm going to give it a try. I wonder if the DO and super glue can be mixed together......?

So, have you had success sanding the super glue to match the surrounding previously sanded surfaces? It's been awhile since I used any CA, and my experience with it was not good.....had too much trouble with the CA staining surfaces, and it was apparent there was an attempt to make a repair.

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The Do often prevents the superglue from staining the wood-but sometimes not-especially soft wood like box elder or pithy spalted maple. If really spalted, you wouldn't even notice the darker wood surrounding the crack from the SGlue as it has lots of lines anyway. What you have to be careful with is after superglueing subsequent coats of DO leaves shiny "shoulders" along the crack (residual DO??) and needs some "steel wooling. " What I really don't know is how good is the adhesion of the SGL when mixed with either old sanded DO, or recently applied SG. Cracks seem stable , but 3 years from now??????
If you think you'll hide the line, in clear wood, I wouldn't get your hopes up..
My process( similar to what John Lucus mentioned with minor tearout on his mirrors=sand with 200, allow the dust to get in crack, swipe with DO, allow a minute or so to "dry", sand litely (so dust with small amount of DO "slurry" is in crack, fine line of SG, allow a few seconds, and maybe swipe gently with a paper towel and then resand with 200, then 320, etc. In light colored woods, The dust will darken and often darker than the surrounding wood with the DO. So with a close look anyone can see it. If real tiny cracks I can;t see them. What have you got to lose????? If the cracks are big=either embellish, relegate to the "seconds" bin, or recycle (in wood stove/fireplace. If the piece is already "finished" and a fine crack appears I do the same thing, trying to blend the sanding with larger and larger areas with very fine sandpaper. (400-600.) I have not tried epoxy. Seems like it'd be a bit messy and not finely applied. What I like about DO is seems to be easily repairable-cussing all the way to "fix it" :mad:
Also I have had experience with cracks appearing and then disappearing (with no treatment) and mentioned this in a previous thread . Locust, Kent coffee tree and honey locust are brought to mind. "to SGL or not to SGL-that is the question"
Gretch

 

[Sergio Villa]

Odie, you said you usually fill cracks with epoxy. Can I ask which size cracks you mean? How you use epoxy in think cracks, in other words how do you allow penetration in a thin crack? Do you know if epoxy will withstand washing?

 

[Odie]

Odie, you said you usually fill cracks with epoxy. Can I ask which size cracks you mean? How you use epoxy in think cracks, in other words how do you allow penetration in a thin crack? Do you know if epoxy will withstand washing?

Mornin' Sergio......

Food bowls aren't what I do very often, but I do a few of them because I have bowl blocks that are more suitable for that, than my more preferred choice of decorative bowls.

Actually, "washing" would be an incorrect term for cleaning a salad bowl. You really don't want to immerse, or soak wooden bowls, and dishwashers are terrible for them. I simply wipe them clean with a damp rag and apply mineral oil afterwards.

A fairly large crack can be filled with epoxy. The best example of this are these bowl photos that I added to my AAW gallery recently. (This isn't a food bowl, but the best example I can think of at the moment for showing a large epoxy repair.) These epoxy repaired cracks are visible at 10 o'clock on the top side photo, and at 2 o'clock on the photo of the foot. These cracks spread pretty wide, about 1/16", or a little larger, and went all the way through both sides of the wall. It may take more than one application to do the job. For the initial application, in order to keep gravity from oozing the epoxy out of the gap, I use a piece of tape on the side facing down.

For thin cracks, I use finger pressure to push the epoxy into the crack. (Use a disposable medical finger cot for this.) You can tell that this works to depth, because during drying, some of the epoxy will ooze back out, and create a little hump there on the exterior of the crack.

You don't want big gobs of epoxy on the exterior surface after drying, but a thin layer is easily dealt with by cutting or scraping with your lathe tools. The surface should be near your final tool finished surface, where only the finest of cuts are necessary for the final surface preparation prior to sanding. The epoxy can be sanded away, but using lathe tools does a much quicker job of final preparation for sanding.


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[Gretch Flo]

Odie-beautiful bowl, beautiful wood. Kind of burl???? I do love your simplistic adornments-don't get all fussy, and ornate on me with the piercing interest that you have written about!!!!!!😀 Gretch.

 

[James Seyfried]

I think with some small cracks such as the one being discussed, DO or other oil finishes may swell the wood fibers and close the crack. I think there is a good possibility that it will stay closed, as the oil cures inside the wood.

 

[Bill Boehme]

... You don't want big gobs of epoxy on the exterior surface after drying, but a thin layer is easily dealt with by cutting or scraping with your lathe tools. The surface should be near your final tool finished surface, where only the finest of cuts are necessary for the final surface preparation prior to sanding. The epoxy can be sanded away, but using lathe tools does a much quicker job of final preparation for sanding...

This is probably worth reiterating to newbies. Trying to level a surface by sanding is tricky business. Epoxy is very hard compared to the surrounding wood. Sanding is very likely to take down the surrounding wood as much as it does the epoxy with the final result being that a step gets transformed into a hump. Something that has been posted numerous times in the past is what I call the "dark side" of sanding. Of course, the good side is that it makes the surface smooth. The dark side is that it changes the shape of the surface because wood is not a homogeneous material. Sanding across end grain and side grain produces different results. Heartwood, sapwood, growth ring density, and knots are several things that influence how the wood sands. The sandpaper might encounter all of these things in a single revolution of the turning on the lathe. The moral of the story is to use lathe tools to get the wood to the point that a minimal amount of sanding will be needed.

 

[john lucas]

I often use thinned lacquer to seal. Wood before filling cracks with CA. Works extremely well.
Regarding filling with epoxy and leveling I use a cabinet scraper. You can level it quite well without creating a lump around the wood. Cabinet scrapers also work wl in cleaning up torn grain areas. With the lath off of course. On torn grain you clean up the area which often leaves a small depression the. Use the same toll to slightly blend in the area around the depression. Most people will never notice it if you then sand everything well

 

[Odie]

Odie-beautiful bowl, beautiful wood. Kind of burl???? I do love your simplistic adornments-don't get all fussy, and ornate on me with the piercing interest that you have written about!!!!!!😀 Gretch.

Oh, thank you Gretch!

It's maple burl, with a streak of curly figure.

Getting the NSK unit is on my list of things I'd like to get. Don't worry, dear lady.....If I do, my plan is to keep it simple!

Simple, yet well done.....that's my goal.

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[Mark Mandell]

Small note on oil fillers.

Oil finishes shrink as their cure; what may start out as a 7-9 mil film is likely to be less than 4 mils thick when the polymerization reaction is complete. Anyone who has done a "piano" finish with oil-based products knows this as the wood's grain and pores reappear in a few months.

Using a oil-based finish as a crack filler (with the included sanding slurry of other "filler") will do ok, however the crack will reappear as a line after a while. That line may be concave or convex as the wood goes through seasonal expansion and contraction. If the bowl were made in a humid "northern location and then taken to say Tucson, AZ or Waco, TX, it should be expected that the crack will reopen as the wood shrinks.

 

[Odie]

Figured I'd better say something in conclusion here. As Mark suggests, the crack did reappear, given a little time. I've concluded that multiple applications of DO will not permanently fill a crack. Because it did fill the crack at first, it was only a "false hope" that it would last.

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