Nanci, Whoever made your counter top sanded it and then applied the finish, oil or what ever and then installed it. Unfortunately, the grain of the wood will naturally expand when it gets wet and raise up like you describe. Water + Wood + swelled grain. Mineral oil, and/or beeswax offers no protection from this whatsoever. The only way to minimize it is to wet the entire surface and then sand off the raised grain. Do this several times, or until the grain no longer changes appreciably when it dries. Once dry, use a catalyzed oil finish like Watco, or if concerned about chemicals you can use a "salad bowl finish".

You want a finish that "sets" or catalyzes to prevent the mineral oil wicking out onto what you set on the counter.

 

What does it mean to have a "catalyzed" oil? Is salad bowl finish different than the mineral or beeswax you would put on? I'm assuming it's food safe and also does not go rancid? From what I've been reading only mineral or linseed does this.

Also, can you talk more about the finish that "sets" or catalyzes to prevent the mineral oil wicking out? Are you talking about sealing the counter with some kind of plastic or urethane that we wouldn't want to get into food? and if it is food safe, can you do this without wetting and re-sanding the counter over and over again?

Third question- Should the people who made our countertops have done this (the wetting and re-sanding) before installing the countertops? In other words should they have been swelling the wood and sanding it over and over again in the shop so that we don't have this issue or is it normal to leave consumers with the issue? The Ikea countertops we bought years ago never did this but we went fancier this time, paid a lot more and I'm wondering if normally this would have been taken care of in the shop.

Thirdly, if we don't wet and re-sand our countertops- because this sounds like a huge job- and it just bubbles in places as we use it, is this the worst thing to let that happen?

Thanks,
-Nanci

 

Kat - mineral will tend to wick out for quite a while and like said above offers almost zero protection. In my opinion, unless you plan on using your countertops as cutting boards, id shy away from the mineral oil. Im planning on doing wood countertops in my home very soon and ill be using General finishes Arm -R-Seal for the finish.

Whats happening with the mineral oil is that its raising the grain of the wood causing it to "bubble". I don't think that it should have been on the people who made your countertop, its a product of the finish not of the craftsmanship. Its very typical for any species of wood, when introduced to water, to have its grain raised.

Personally I wouldn't leave the tops untreated. Eventually the moisture (water) will cause your joints to fail and delaminate. The sanding isn't that big of a job in reality. You can easily do it by hand with a 220 or 320 grit one the mineral oil has dried/evaporated. You're only taking off the grain that has raised you're not flattening the entire piece.

We're gonna get you squared away but its gonna take a little bit of time and effort on your end of things to make it right.

Could you tell us a little more about the countertops .. what type of wood are they? Which way are the board oriented? All of these things will cause different issues that will need to be addressed. A couple of pics would go along way too.

 

I agree with chrisstef Mineral oil is not a finish it's a treatment. Clean the counter top with naphtha (it may take several times) make sure the area is well ventilated,after words sand with 220 to 320 as chrisstef suggested wipe down and apply the Arm-R-Seal again make sure you have good ventilation. A second coat is a good idea ,just do a light sanding with 400-600 sandpaper.

 

Nanci, It's a slow morning here so I'll try and explain. First, I have been doing wood work for over 30 years, and have worked through the issues you are describing. I have also worked with laminate, solid surface, and stone countertops and I know those industries well.

What does it mean to have a "catalyzed" oil? Is salad bowl finish different than the mineral or beeswax you would put on? I'm assuming it's food safe and also does not go rancid? From what I've been reading only mineral or linseed does this.

A. "Catalyzed" means that chemicals have been added to the oil to cause it to set up and harden, or "dry". Varnish is an oil finish that does this and "penetrating oil" finishes are designed to soak into the wood and then harden.
B. I do not believe that "Salad Bowl Finish" is mineral oil/beeswax. It is designed with non-toxic dryers to be food safe. Behlens makes it, do a search.
C. Organic oils like cooking oil do go rancid over time. Mineral oil is the same stuff that you put in the car, but without additives. It never hardens and will soak out of the wood forever. Linseed oil is a plant seed oil, commonly sold as "Boiled Linseed Oil". Read the ingredients as there may be chemical driers added. When you get down to toxicity of finishes, it really gets down to how much you plan to ingest and how much chemical you are willing to tolerate. Your call on that one.

Also, can you talk more about the finish that "sets" or catalyzes to prevent the mineral oil wicking out? Are you talking about sealing the counter with some kind of plastic or urethane that we wouldn't want to get into food? and if it is food safe, can you do this without wetting and re-sanding the counter over and over again?

A. I'll answer this one end to beginning. The nature of wood is that it is basically a matrix of little cellulose cells, hollow inside and able to absorb water very easily, much like a sponge. When those cells fill up with water, they swell, hence your problem. A piece of wood 25" wide could swell ¼" over the width if allowed to absorb plenty of water, and this is also why wood cracks when it dries out. You really cannot prevent this from happening and that is why wood is seldom used as a counter top material, particularly where there will be water. You can, however, minimize the symptom by forcing the wood to swell (wetting) and then slicing off the expanded cells with sandpaper. It works rather well, but is a pain to do.
B. The "sealing" or varnishing concept does not work too well as the water will get in under the varnish and will cause it to split, lift, and separate as the wood moves underneath.

Third question- Should the people who made our countertops have done this (the wetting and re-sanding) before installing the countertops? In other words should they have been swelling the wood and sanding it over and over again in the shop so that we don't have this issue or is it normal to leave consumers with the issue? The Ikea countertops we bought years ago never did this but we went fancier this time, paid a lot more and I'm wondering if normally this would have been taken care of in the shop.

A. The contractor who built your countertops, in my opinion, should have discussed the inherent issues with using wood for counter top applications with you before taking on the job. Wetting and re-sanding is labor intensive and not conducive to profit, and therefore they would not want to do it without being paid accordingly.
B. Since you did not see the issues with countertops from Ikea. I suspect that they were sealed with a penetrating oil finish from the factory. Since you did not see bleed out, the finish had hardened in the wood so whatever they used had dryers in it. Whether or not they were "food safe" is anyone's guess.

Thirdly, if we don't wet and re-sand our countertops- because this sounds like a huge job- and it just bubbles in places as we use it, is this the worst thing to let that happen?

A. You will get patina. As the wood is used, the surface will raise a bit and some of the color will fade away, especially where it is wet often. Once the grain raises, it won't really raise more over time. Think of it as a "traditional wood countertop look".

 

Thank you so much for taking the time to explain all of this. I really appreciate it.

 

I'm a long term woodworker too and hydro gave you very good advise.

 

I don't know Hydro and didn't read his article above but I do know that a1Jim IS a long time woodworker, teacher and he does know his business. I am not implying that others don't know woodworking but I do like what I know about Jim. I am just saying don't rule him out because he doesn't give lengthy answers. Good luck

 

Thanks for your support Grandpa.
I do feel hydro did a great job of fielding Katgril's questions.

 

Thank you so much, guys. The wood is hard or rock maple and the wood runs along the length or the counter top, parallel to the walls.

One last question (maybe not the last). Chrisstef mentioned needing the mineral oil to try before applying sealer. Is it necessary to feel like the mineral oil is gone from the wood before applying sealer? If it's sealed in would that be problematic? I had assumed it wouldn't hurt the wood.

Thanks again, everyone, for taking the time to answer my questions. You've been really helpful.

-nanci

 

Like Jim said you're going to want to wash down the wood where the mineral oil has been applied with Naptha. If you don't you may not get the new finish to bond with the wood. Basically you don't want anything in between the wood and the new finish or you'll have issues. Naptha can be found cheaply at home depot or lowes in the paint department.

 

Mineral oil never gets hard so its always fluid.(That's why its a treatment) When you go to seal the wood with whatever finish your using you will need a good clean surface to apply the new finish. Otherwise whatever finish you may be using may give you any number of problems from not leveling out to not curing / reacting with the mineral oil. If you don't get the mineral oil off, the results will be disappointing. If you don't, you will have to strip both your sealer you just applied and the mineral oil (more time and $$). Above, A1Jim said wipe down the counter with Napatha that's basically a fast drying solvent that will help clean the mineral oil off your counter. Overall the advise here has been very good, you shouldn't have any issues if you follow the advise above.

Good Luck

edit: chrisstef types faster than me…