Watco Butcher Block food safe finish problem

[Phillip Medghalchi]

Hello, Turners.
I am in a great need for advise on this product as it messed up a beautiful CA Walnut corred bowl (3 pieces).
Here is the problem: I have used this finish on other woods like Mesquite and Spalted Bradford pear with no problem, however when I tried to put it on the Walnut bowl series I am getting these streaks and blotchy spots all over it. I even contacted Rustoleum ( Watco is their brand) and told and sent pictures and no advise form them. I have called to many turners that I respect their opinions and they didn't know what to do with it. Please bear in Mind that I am a member of Alamo wood turners club as well as Hill Country Turners, Yesterday I took them to the meeting and I couldn't get much help.

I do not have the initial enons on these pieces and I am trying to resort not to making waste glue blocks and gluing them to the bowl bottoms ( chances of not getting it true on the glue block and finally sand the whole thing down to bare wood and start again. I have been hung up on this issue for more than a month and would really like to finish this project and finally send them to my daughter (has been waiting for more than a year)
Any help to save me form the grief of sanding it to the bare wood would be greatly appreciated. I try to [ost the pictures If I can figure out how.

[Ted Calver]

Phil, AFAIK, this stuff is a very thin oil designed to penetrate into end grain on butcher blocks. I wouldn't choose it for a film forming finish on a bowl. I use it on end grain cutting boards and one flooding application on the top will often penetrate all the way through the board. What you are seeing IMHO, is the result of the product penetrating the end grain of the bowl and staying on the surface of the side grain. You will need several more coats on the end grain for it to be saturated enough to form a surface film, and even then I don't think it will match the side grain. If it will help, I put two coats on my cutting boards, letting it dry for a couple of days each coat, then apply a walnut oil/beeswax paste and buff to a soft luster. That might work for your bowls. Apply the additional coats, wait for it to dry, Beal buff with tripoli only (not white diamond, it will fill the walnut pores and look terrible), then try the Mahoney's Utility Finish/Doctor's WoodShop Walnut Oil finish beeswax mix (four parts oil/one part beeswax). Just my 2¢

[John K Jordan]

I've never used that finish. What is in it?
Maybe it needs to be applied somewhat like Watco danish oil, a blend of oil, poly, and solvent.

The procedure for the "danish" oil:
0. Start with the surface perfectly smoothed and sanded:
1. Apply finish liberally. Some soak the piece in the finish for deep penetration on end grain.
2. Wait 30 minutes or so and completely wipe off any excess remaining on the surface.
I continue to wipe as long as I see bleeding on the surface.
If I still see dry spots on the end grain I may continue applying to that area then wipe of the excess.
If the excess is not removed from the surface, it will dry and make a mess.
3. Let it dry/cure for 24-48 hours or more. Finish that penetrated deeply into end grain may need longer time.
4. Lightly wet sand if desired using the same oil.
I wet sand if the dried surface doesn't feel completely smooth.
If I wet sand it is usually with 600 grit sandpaper or 0000 steel wool.
5. Apply more finish, a light coat, use extra if it's still seeping quickly into the end grain.
The entire surface should look uniformly wet.
6. Wait 20-30 minutes then completely wipe off any oil on the surface.
7. Let it dry overnight.
8. Repeat steps 4 thru 7. I sometimes apply 6 to 10 coats.

To avoid burning down the shop use proper caution with paper towels or cloths used to wipe off the finish.

This method is not fast but can result in a beautiful soft "satin" sheen. For more gloss let the piece continue to dry for a week or more then buff.
All this, of course, is with the "danish" oil, perhaps an alternative. All finishes are "food safe" when cured.

penta_jatoba_IMG_7636 - Copy.jpg

It looks like dried finish on the surface of yours in places. If it were me, I'd remove all that with solvents and curved hand scrapers and sanding and start over.

Just curious, what is the dark straight line visible across the inside of the bowl in the first and second pictures?

JKJ

[Robert L Stewart]

My experiences using the Watco danish oil for the past 20 plus years is exactly the same as John Jordans.
It is an excellent product, needs lots of patience to achieve it's magic.

Robert

[Brice Rogers]

I googled it and looked at the MSDS. Surprisingly, there is a California proposition 65 warning: "WARNING! This product contains a chemical(s) known by the State of California to cause cancer. " That isn't very comforting for something that is supposed to be or is assumed to be food safe. But the list of prop 65 chemicals is probably over-reaching.

I'd suggest Mahoney's walnut oil next time. Or Mahoney's and wax.

[John K Jordan]

I googled it and looked at the MSDS. Surprisingly, there is a California proposition 65 warning: "WARNING! This product contains a chemical(s) known by the State of California to cause cancer. " That isn't very comforting for something that is supposed to be or is assumed to be food safe. But the list of prop 65 chemicals is probably over-reaching.
I'd suggest Mahoney's walnut oil next time. Or Mahoney's and wax.

The Prop 65 list includes aspirin, coconut oil, ethyl alcohol (in alcoholic beverages and denatured alcohol), aloe vera, nicotine, cocaine, tobacco, nitrous oxide, oral contraceptives, salted fish, and tobacco and marijuana smoke. Oh, and wood dust and urethane. Maybe that finish has some of those.

https://oehha.ca.gov/media/downloads...list010320.pdf

But as usual, much depends on context: e.g. drinking quantities of alcohol vs using it as a solvent which evaporates.

[Pat Scott]

Did applying a heavy coat as in the last picture help at all? You might try soaking the bowl in a bucket for a few hours, or wet sand as others have suggested. Otherwise if it still looks blotchy it might be time to let it dry for a week or two and then sand back to bare wood and start again. You'll clog up sandpaper very quickly so don't be surprised to go through a lot of it. Cleaning the sandpaper with a rubber stick that they sell for that purpose can help some, but I still go through a lot of sandpaper. Once sanded I don't usually use a sanding sealer on Walnut but you might try it before reapplying a different finish such as Danish Oil.

[John K Jordan]

...let it dry for a week or two and then sand back to bare wood and start again. You'll clog up sandpaper very quickly so don't be surprised to go through a lot of it. ...

Note that using scrapers to remove the finish might avoid a lot of sandpaper clogging.

I grind traditional cabinet scrapers to various curves (grinding with a 1" belt sander creates less heat) then sharpen and burnish just like cabinet scrapers. These will remove the finish on the surface and as much as you want past the surface, smoothing the wood as well. After such scraping, unfinished pieces hot off the lathe are smooth enough I can usually start sanding with finer sandpaper such as 320 or 400, or even finer on occasion.

scrapers_.jpg scrapers_favorite_IMG_7870.jpg _scrapers_IMG_7818.jpg _scrapers_IMG_7819.jpg

JKJ