You could try sanding down the butcher block and applying at least four coats of wipe on Polly. I like Watco semi gloss but there are other good brands. An oil finish might not be the best choice in a van. I think most people use poly and wipe on poly is the easiest to apply.

A100 grit finish is fine enough. You don't need to get carried away.

 

Sanding and bleaching (or something like X14) may address the mold issue. But could change the appearance of the wood as well.

If you’re going to seal it with a film finish (like poly, varnish, epoxy, etc.), be sure to do both top and bottom. If you don’t you may experience a more stable top and a less stable bottom, meaning the bottom will expand and contract at a much higher rate than the top, causing crowning and cupping with changes in the air moisture. You can see plenty of youtube van videos with warped butcher tops for this very reason.

 

I'd remove the plumbing and sand. Treat with some very light beach solution to make sure you kill the mold. Then re-apply your food safe coating. Repeat the coating often.

TBH, wood counter tops are prone to this issue. I once made a beautiful custom counter of quarter sawn oak at great expense for my sister at her request. It was gorgeous when it was done. But in spite of her trying to take good care of it, it got stained and eventually she replaced it. I still have the cutout for the sink, I use it as an extra large cutting board when canning and BBQ'ing.

 

Thanks everyone! I appreciate it. @Boondox just what I needed to hear. It seems like some of it is pretty deep- Just keep sanding?

 

Within reason, yes. You might try a bleach treatment and then see how it looks.

Since I assume you don't really prepare raw food in direct contact with the wood, something like the poly finish that has been suggested might be a better option. Once done, make sure to dry the counter after use and control humidity in the van.

 

Traditional butcher block was always maple. Very dense hardwood so you could use an oil finish to fully cover and treat the surface.

Today, any wood is used for a " butcher block" look. If these woods have any pores or cracks, the finish does not fully flood the pores and cracks. The surface tension of the finish won't let it fill gaps. Oak and mahogany are examples of wood have pores that should be filled prior to finishing with a wood workers pore filler. If not, the pores "break through" the finish and leave tiny holes. The filler can be tricky to work with at first, but it fills the cracks and pores so the finish film is uniform across the surface. This eliminates things from getting into the wood and staining the untreated wood.

I have only gone over filler with (edit added) solvent based polyurethane. I have not tried it with oil rub. I don't use water based poly finish.

I would follow @Boondox advice. If you do decide to try a filller, use after bleaching and before sanding. The filler comes in clear, is spread with a trowel, and sanded to remove the filler on the face of the wood. It any remains, the finish can be blotchey. Good luck.

 

Traditional butcher block was always maple. Very dense hardwood so you could use an oil finish to fully cover and treat the surface.

Today, any wood is used for a " butcher block" look. If these woods have any pores or cracks, the finish does not fully flood the pores and cracks....

And real butcher block was end grain.
Bowling alley lanes are not "butcher block".

 

Since this is frequently wet area, once you get it cleaned up enough to be acceptable a sealing product is preferable to just treating like you would a cutting board.

Not sure how your butcher block will be if you go the poly route, but when I used to do a lot of custom woodworking, I found that water-based coatings often raised the grain, so oil based for a first coat was preferred.

 

A counter in a van is in a very different environment than the counter in your house. Vans go through frequent temperature and humidity extremes. I think that an oil based poly is a more appropriate finish.

 

If you’ve used a 10% bleach solution, you don’t have mold.
Your pics don’t even look like mold. Don’t use oil based poly if you want food contact.
Mineral oil and wax are food safe. Mineral oil never goes rancid.

 

Not sure what you are getting at here - there in nothing wrong with using a clean polyurethane surface for food prep. Polyurethane is a tough, inert and stable crosslinked polymer. They are all oil-based although many now use water-based solvents to apply them.
Mineral oils are a byproduct of crude oil refining, essentially paraffin oils.

 

The sole purpose for actual butcher's blocks in actual butcher's shops is to provide a working surface for cleavers and knives to chop and carve animal parts without dulling the blades. By regulation and good practice, they are bleached, scrubbed and scraped at the end of every day - developing a deeply curved surface after years of use.

IMHO "butcher blocks" have no purpose outside of a butchering operation and are a very poor and potentially un-sanitary choice of material for a countertop - unless you plan to bleach, scrub and scrape them every day.

OTOH wood counter tops can be sealed using marine grade polyurethane. It's laborious to do properly and as long as you don't cut or scratch through it, should look pretty good for a couple of years or so before needing to be sanded and re-finished. I wouldn't want to trust any oiled wood surface to be sanitary for food prep.

 

Hey all, thanks for all the feedback! Lots to consider here. I think I’ll probably use a filler and sand/refinish etc. Whatever it is, it’s definitely mold. It’s deep, too. It’s a result of not finishing and keeping up the wood properly. As mentioned in my OP, I have tried bleach with no luck. Will update this thread as I sort it out!

Not sure why anyone on here would start bashing butcher block- It’s really not helpful, and seems a little mean/unnecessary. I’ve had butcher block before in various applications with no problems- As long as it’s finished and maintained properly, which it wasn’t here.

Thanks again for everyone’s feedback and I’ll keep this updated!!! Will probably try an oil-based poly like @rf17830 mentioned. @Boondox I do set food on it from time to time, which is why I’d originally tried the Watco. But sounds like maybe I’ll need to compromise on that if I want a better finish I guess the other option would be to sand and try the Watco again, maintaining it religiously this time. I really didn’t continue re-oiling it regularly the way I believe you’re supposed to..

 

Hey all, thanks for all the feedback! Lots to consider here. I think I’ll probably use a filler and sand/refinish etc. Whatever it is, it’s definitely mold. It’s deep, too. It’s a result of not finishing and keeping up the wood properly. As mentioned in my OP, I have tried bleach with no luck. Will update this thread as I sort it out!

Not sure why anyone on here would start bashing butcher block- It’s really not helpful, and seems a little mean/unnecessary. I’ve had butcher block before in various applications with no problems- As long as it’s finished and maintained properly, which it wasn’t here.

Thanks again for everyone’s feedback and I’ll keep this updated!!! Will probably try an oil-based poly like @rf17830 mentioned. @Boondox I do set food on it from time to time, which is why I’d originally tried the Watco. But sounds like maybe I’ll need to compromise on that if I want a better finish I guess the other option would be to sand and try the Watco again, maintaining it religiously this time. I really didn’t continue re-oiling it regularly the way I believe you’re supposed to..

I'm guessing that's me.
I'm poking fun at the term "butcher block" and clarifying how they are supposed to be used and made safe.
What you have is a wooden countertop. It could only work as a butcher block - if you bleach, scrub and scrape it every day, as butcher blocks are intended to be.

There is nothing "mean" intended, just an explanation of the facts, context and correct use - so you avoid risk of food poisoning. In them old timey days, when disinfectants were few and food poisoning was common, porous wood surfaces were considered inappropriate for frequently wet and food contacting counter tops - "only fit for the poor house" - to use an 18th century term
Everything about vans, boats and trailers, exaggerates the weaknesses of a material.
With meticulously applied modern marine grade polymer sealants, wood can be made to work.
"Oiling" is a very poor and potentially unsafe substitute for food preparation surfaces: 1) many pathogens and toxins are oil soluble and will soak into the wood, 2) water will still find its way through an oiled surface.

IMHO, the mold that you have, should be bleached and scrubbed out. If bleaching and scrubbing doesn't work, you should consider replacing the affected area.

Sorry if I offended you, that was not my intent.

 

It is generally accepted that almost all film finishes are considered “food safe” once they are fully cured. Film finishes are not considered food safe if the surface is used to cut on, like most “butcher blocks”. Butcher block countertops that are not used as a cutting boards should be fine with a film finish, even for food contact. But if they are used with knives or other utensils that could scratch them then particles of finish could end up in your food.

I love the look of butcher block countertops, but I would never install them where knives or water will be used. Solid wood will always expand and contract across the grain with changes in air moisture, no matter what type of finish is used. And that has to be dealt with in your construction techniques. I suspect the popularity of them in vans has a lot to do with what people see others have done on youtube. They are cheap and readily available at Home Depot, and easy to machine to size. My preference (once I get my van) will be some type of resin-based product like Corian.

 

I use a thin bamboo cutting board for cutting, which I store in my silverware drawer. My acacia counter tops came pre finished with oil. I gave them a light sanding with 100 grit sandpaper and applied three coats of oil based wipe on poly right over the oil. The coating bonded and worked great. Oil can be a good base for poly.