[OP]
Member
Everyone Ive talked to agrees that none of the oil finishes will make a bowl watertight.A lot agree also that any finish is foodsafe after it cures.With that being said what are the choices for a watertight,foodsafe bowl?Something just doesn't feel right about eating off a urethane coated plate or bowl .Theres a pretty limited amount of food that is not pretty wet when it is served,at least in the south.What are the options? Thanks
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I doubt if any finish would be completely "watertight" most will shed water for awhile but a bowl filled with water will eventually fail IMO.
I use WOP or Tung oil on most of my bowls.
[OP]
Member
Daryl do you use your WOP bowls for food such as soup or beans ?Anything with lots of water in it?Originally Posted by daryl moses
Member
there is 2 part epoxy finish that they use on bar tops , I think it is called viratex maybe. it can be poured on around 1/4 inch thick I think? But on a bowl that would be a trick! I saw a table top with a wooden form around the outside and the interior was filled with different brands of beer bottle caps and poured over. neat stuff
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[QUOTE=Sonny Kemp;2601195]Daryl do you use your WOP bowls for food such as soup or beans ?Anything with lots of water in it?[/QUOTE
None of my bowls are used for soup or beans. And I hope the bowls I sell are not used for them. I advise anyone who purchases one to use it as a salad bowl, fruit bowl, etc. and to NEVER put one in the dish washer.
Contributor
Sonny,
I investigated this fairly carefully a few years ago when I made a set of salad bowls. The authority is Bob Flexner and you can find an article by him on the web. There is also an article in Fine Woodworking by Johnathan Binzen that you might be able to find on the web. I used wipe-on polyurethane. The bowls have held up very well for years, except that sometimes they get left in water by accident.
You just don't feel right about eating off a cured polyurethane surface? No reason behind that? Some people who feel the way you do use mineral oil or even paraffin (canning) wax on cutting boards and salad bowls but it has to be renewed fairly often. Some people use beeswax or carnauba wax or some mixture of two or three of these. They last a bit longer but still have to be renewed. Pure tung oil (NOT a blend labelled Tung Oil) or walnut oil are edible AFAIK and will slowly dry and provide some protection.
The most waterproof finish would be epoxy. MaxClr claims to be food safe. I have not tried it. Some epoxy finishes have a mild odor from the hardener. You can also buy odorless epoxy.
Doug
Member
If it is for your own use, I would use Polymerized Tung Oil, it is water resistant (not water proof) you can IMO eat sloppy wet food out of that, rinse the bowl and dry it right after the meal, it should last a long time.
Remember people used to and still do at places, eat from plates that have no finish at all, I’m quite sure Reed Gray (Robo Hippy) uses a wooden bowl/plate to eat from and has for years.
Wood like Poplar and Willow was used a lot for that, as it is pretty tough and easily hollowed (not turned), open grain wood like Red Oak or Honey Locust, Walnut etc, I would not use for it though.
If the bowl gets to be unusable, it’s not hard to make another one
Have fun and take care
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For what it is worth, I turned a hollow walnut vase a couple of years ago for a friend and spread a double layer of epoxy on the inside. I used a cheap silicone spatula that worked very well and gave a smooth finish as far down as I could feel. Not perfect, but good enough for the inside of a vase. It has held water for days at a time without any noticeable leaks. it even has a 1/8" crack all the way up one side of the vase that I filled with coffee grounds and CA. Looks intentional
As a test I sealed the inside of another, smaller walnut vase with clear silicone to see how well it would hold water. I left water in it for 2-3 weeks without it leaking, but it is nearly impossible to get a smooth finish with that stuff, and as a coating it is incredibly messy. There's also no way to sand it smooth or scrape it off the inside unless you can still chuck it up, but I'm not sure that's a good idea either. Probably wouldn't be great for a bowl sealer, but thought I'd throw it out there anyway.
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I would reconsider wanting a watertight finish on a bowl that is going to be used to serve food. To make it watertight means to cover it with a film finish, which also means a rigid hard finish that is not flexible. Wood is going to move, and all it takes is a slight movement of the bowl to create a crack in the finish which water and bacteria can penetrate. My bowls that I use Danish Oil, or even Walnut Oil on, will still be going strong long past your bowl with epoxy or whatever watertight finish you use.
"Something just doesn't feel right about eating off a urethane coated plate or bowl". If it's a heavy coating of urethane or polyurethane, then I might feel the same way. But if it's a light thinned coat, or several light coats that soak into the wood then there shouldn't be any concern. We've been eating off wooden plates in my household since 2011. We use 11" dinner plates and 7" appetizer/dessert plates, and the appetizer plates are used every single day, and washed and dried every single day. I used Danish Oil on them, and I've only had to re-oil them once in 5 years. All of the bowls that we use were finished with Danish Oil also, and I have yet to re-oil any of them.
Danish Oil is a generic reference that means a mixture of oil/resin/carrier. The oil (Tung or Linseed) soaks into the fibers and enhances the grain. The resin (urethane or poly) also soaks into the wood to fill the cells and provide protection. The carrier (Mineral Spirits) thins the oil and resin so that they can soak into the wood, and not stay on the wood. You've already said that once a finish cures it is foodsafe. Once Danish oil cures it's food safe. Just stick your nose right up to the plate or bowl and sniff. If you can still smell the finish it's not done curing. Since there is resin in Danish oil, it is possible to build up a film finish if too many coats are applied. Wiping Poly is nothing more than regular poly that's been thinned. If you put on too many coats of wipe on poly, or too many coats of Danish oil, they can build up a film. The key is to stop before that happens. Usually 2-3 coats of Danish Oil is all that is needed.
[OP]
Member
Thanks Pat for your reply.What Im referring to as a watertight finish is one I can put food that has a lot of water or liquid in it and it not get the outside wet.I have tried several with walnut oil and they all quickly within a few minutes get the outside damp.Thats 3/4 coats and a day or more between coats.The only thing Ive used successfully is 2/3 coats of wipe on poly and was just unsure if they were actually foodsafe.I don't know is why Im asking here.
Member
Walnut Oil wouldn't be my first choice in that application. I don't think you said what kind of wood you're using? Open pore woods (Ash, Oak, etc), would of course be harder to seal than Maple or other close pore woods. I made a set of Silver Maple cereal bowls that we use in the morning for our cold cereal with milk. The inside stays wet for as long as it takes you to eat the bowl of cereal. When done eating we rinse them out and turn them upside down in the sink until we do dishes at night. No leaks or any other problems after 4 years of use. I think I used 3 coats of Danish Oil when I made them, and I haven't re-oiled them yet.
I know wipe on poly is just thinned regular strength poly, but for a bowl, plate, or platter, I might be tempted to thin it even more with Mineral Spirits. If you've used it successfully as it comes from the can, then that's good. You want it to soak into the wood and not build up on the surface, which is why I might thin it even more (to make sure it soaks in).
Member
Another County Heard From: What is the point, really? I'm not sure, but I'm guessing that long, long ago, wood was the choice for bowls and eating utensils right after hands and fingers, and maybe in between depending on local. A wooden bowl can be used for soup-- why not? As long as you don't mind the flavors of last night's soup on the next day. We have lots of wooden bowls and plates and platters. One cutting board is even branded with a "NO GARLIC" brand to avoid adding unwanted flavors to fruit. Otherwise, you get all sorts of flavors using wooden utensils -- can't be avoided without obedient branding recognition.
If you want waterproof you use china, plastic, etc.
Member
Like Pat I would steer away from walnut oil(never hardens) and wipe on poly. Any poly is impossible to refinish like tung oils. Nothing sticks to it and requires sanding back to raw wood for refinishing. Mineral oil works fine on bowls and cutting boards--easy and fast to renew.
Member
There is nothing wrong with eating off polyurethane. It is one of the commonest plastics around. If you have a surgical implant it is most likely partly or completely polyurethane. Polyurethane is hazardous as an aerosol when spraying it but once it is cured it is perfectly safe. Whether it is suitable for sealing a turned bowl is an entirely separate issue. I personally prefer an oil finish and maintain it regularly. Cheers
Every construction obeys the laws of physics. Whether we like or understand the result is of no interest to the universe.
Member
With respect, I have to disagree on something:
"...steer away from walnut oil(never hardens)..."
I've heard this several times and I don't understand where it comes from... Walnut oil (like all pure oils) certainly doesn't form a hard plastic film, but it does indeed cure (though it takes longer than finishes with driers in them like BLO and much longer than resin/oil blends like Danish oil). I use it for some bowls and then usually put them in a warm place (my attic in the summer or near the woodstove in the winter) to cure. Depending on the wood it can take up to a month to cure, but it does get there (though a word of caution on very porous woods like oak -- the pores suck it up like drinking straws and it will not cure in any reasonable amount of time in them). Mineral oil, on the other hand never cures. It just... is. Not to say it's a bad choice. It just doesn't polymerize like drying oils do. I also agree that it's very easy to renew -- especially given that you don't have to wait for it to cure. No idea how well it (or any other finish for that matter) would block moisture in the food from seeping into the wood, though...
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