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How to Waterproof Wood for Bathroom

When the wood you use in designing the floor of your bathroom or the vanity of your sink and dresser is constantly greeted with moisture, deterioration is imminent.Since this is the sad reality on the ground, how then do you protect the wood from moisture? How do you retain this beautiful wooden floor finish without incurring the wrath of the waters and so the big question lingers – How to waterproof wood for a bathroom to avoid the damage being caused by moisture ever-present in your bathroom?

Well, the good news is; this article will answer that boiling question. All you need to do now is to continue reading.

Photo: 123rf.com

How to Waterproof Wood for Bathroom

There are three fail-proof methods you can use to waterproof your wood in a bathroom world where water rules.

But you need to know this first: there’s a thin line between waterproof and water-resistant woods.

So when next you are assured that a certain piece of wood is water-resistant, it means it can resist water to a certain limit but at the end, it will finally bend to the resilient forces of water. On the other hand, waterproofed wood means that the wood is forever protected from the forces of water.

That’s the angle I’ll be showing you in this article. You waterproof your wood forever with the three methods below. Three fantastic options and once the choice for you to make. We’ve had much ado already on introductions, so let’s begin with the first method.

First Method: Waterproofing Wood with Oil

There are three oil options you can use to waterproof your wood. There is linseed oil, walnut oil, and tung oil. Whichever oil you decide to use, the following procedures will help you waterproof your wooden bathroom decor and keep the waters at their bay.

  1. Mix the oil with either turpentine or apple cider vinegar to obtain a more powerful waterproofing oil. Ensure you stir thoroughly. This isn’t a must as you can still use the oil singly.
  2. Prepare the wood surface by using sandpaper to smoothen rough surfaces and edges. Rough surfaces will become visibly evident and appear distasteful when you are through with the oiling, that’s why this step is important.
  3. Dip a soft-bristle brush into the oil (whether it’s the mixture or single oil) and apply thoroughly around the wood leaving no surfaces and edges untouched.
  4. Allow the surface and edges of the wood a little time to absorb the oil this will enable you to identify untouched areas and then you can do the needful by reapplying on those areas.
  5. Let the wood to absorb the oil again and then clean off oil residues with a clean dry rag.
  6. Allow the wood time to dry. Oil mixtures dry faster than single oils. Drying time could take a couple of hours or even half a day if you use a single oil.
  7. After you’ve allowed the wood to dry, you can then reapply the oil again on the dried wood surface if you’ve got more to ensure it’s heavily finished and waterproofed.

Other Things to Note about using Oils

  • Although some oils come mixed with other chemicals, you can do the mixture yourself and freely experiment as you continue with the process after a long while.
  • If you are purchasing an already blended oil, then know it has three parts namely: the linseed or tung oil, mineral spirit, and polyurethane. The mineral spirit and polyurethane are added to the chief oil (Tung or Linseed) alongside the turpentine and stirred thoroughly before application.
  • You can obtain the linseed oil naturally and boil it before application. You can always find ready-mades in DIY markets any day.
  • If you desire a thicker combination, keep the mineral spirit addition minimal.
  • The addition of polyurethane can increase or reduce the drying time. Add more if you want a quick drying time. Add less if you want extra time to work more before it begins to dry off.
  • After application and drying, give the wood some time to settle and absorb what it had just received. Hours won’t be enough. A couple of days would do. Don’t ever use immediately after the finishing.
Oily rags are combustible so while you rag away oil residues for re-application, remember to wash the rags with soap and water.

Second Method:  Using Sealants for Wood Waterproofing

Photo: 123rf.com

This method entails using sealants to waterproof woods. The steps for application are almost the same as that of oils.

The only deviation here is that you don’t necessarily have to mix the sealers with any other natural or synthetic chemicals. But you have to wipe the wood dry, sandpaper it and that does it for the preparations before application. You can apply the sealer afterward by either spraying or using a brush. Allow to dry after the spraying or application with a brush is over. Then apply two more times to ensure your wood is well guarded against water.

Other Things to Note about Using Sealants

  • To obtain perfect results, apply sealants at room temperature, temperature above this can affect the potency of the sealant.
  • Do not stir or shake sealants. They are not like other liquids that require vigorous shaking to enable the content to circulate all-round the container.
  • They dry faster than oils, but you still have to allow the air to free passage anywhere the application is being done.
  • After application and drying, give the wood ample time to absorb the protection it has received before you start using it. Any time from 3 days would be enough.

Third Method: Waterproofing Wood with Stain and Sealer

Photo: 123rf.com

This happens to be the most efficient and classy method of waterproofing wood for the bathroom. Why? Because you can choose to use stains alone or you can do a powerful stain-sealant combo. These stains when applied are translucent. Lighter stains come with more oil. They are best used for interior woods like your bathroom which is the center of everything detailed here.

The application process isn’t anything different from the other two. Wipe the wood dry, sand to smoothen the surface and limit imperfections on the job, and then apply with a brush. Allow to dry, remove residues with a clean dry rag and reapply up to two or three times afterward for a thorough finish. This applies to both stains and stain-sealant combinations.

Why Stain-Sealant Combination is the Ultimate

Stain-sealant waterproofing combinations are the best when it comes to effective waterproofing and the addition of styles to the job.

They come in a variety of colors. That you want to finish your wood for waterproofing doesn’t mean it should lose its aesthetic appeal.

These colors are products of color pigments with the inclusion of binders like oils, water, or alkyl-based binders.

Stain-sealants hardly build up on the surface, they are absorbed into the wood as soon as they are applied, so it’s needless to wipe off residues because they would have evaporated before you do so. Alkyl-based stains, however, leave residues on the wood surface.

Other Things to Note about Stains and Stain-Sealant Combinations  

  • If however, you intend to use them for exterior woods, you need to find exterior grade stain for that purpose and you would have to keep up with waterproofing at least after every two-year interval.
  • Stain-sealant combos with color pigments and binders that are oil-based are best recommended for interior woods just like the one you would be using in your bathroom. But their alkyl-based counterparts in spite of the build-up they leave on the wood surface offer a more aesthetic appeal to interior woods.

Frequently Asked Questions

Wood can be used in bathroom or showers as long as sealers applied to it is maintained. If wood is taken care of, it will last a long time.

Did you find this FAQ helpful?
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Yes, waterproofing wood for the shower can be achieved by using sealers.

They’re usually a clear/transparent finish that goes on the outside of the wood. Sealants such as polyurethane, varnish, and lacquer give excellent waterproofing and can be used for showers.

Did you find this FAQ helpful?
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There are different methods to waterproof bathroom wood but using a sealant is one of the best methods to do so.

Sealers can waterproof the wood, they can also prevent wooden surfaces from getting scratched. They are often a clear/transparent finish that coats the wood’s exterior surface.

Sealants such as polyurethane, varnish, and lacquer give excellent waterproofing. They’re brushed or sprayed over sanded, clean wood, then softly re-sanded and re-coated when they’ve dried fully. They offer high moisture resistance compared to the oil finish.

Did you find this FAQ helpful?
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One of the best sealers for wood in the bathroom is spar-urethane.

It’s frequently used on submerged wood, like boat hulls. This particular finish is intended to endure the weather on the hardwood poles that hold a boat’s sails, commonly known as the ship’s spars.

Spar urethane was designed to endure difficult circumstances and preserve the ship’s spars since this piece of wood must withstand severe wetness and wind.

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One of the best wood for bathrooms showers is teak.

Teak is one of the few hardwoods that can withstand damp circumstances due to its low shrinkage in changing weather and great resistance to rot, fungus, and mildew. It has natural anti-slip qualities and is remains the most often used material for boat decking today.

Did you find this FAQ helpful?
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Conclusion

Although they appear rustic and yes they truly are rustic and you can call them antiquated, no doubts, but they make the finest of furniture and cabinetry. These natural building materials called woods to need protection from moisture. Wood and moisture can never harmonize, not now, maybe in the nearest future.

Your choice of the method here is dependent on the budget you’ve set aside for the project. If it’s a big project that involves the entire house you can go for the last method; stain-sealant, which offers more efficiency and saves time. Remember to take some thumb rule precautions like using gloves. You are dealing with chemicals and not just liquids.

Wash your hands after you are done with the entire process, including the tools you used. Don’t forget to keep out of reach of children.

Water shouldn’t be a reason why you can’t have that rustic goodness on the floor of your bathroom, the vanity of your sin or dresser or anywhere around your bathroom you intend using the woods. This is why you need to arm yourself with this information on how to waterproof wood for the bathroom.

William Stewart

The proud owner and lead writer of WoodImprove.com. Started writing in 2018 and sharing his love and passion for wood treatments and crafts.

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Maddie Broad
9 days ago

Hi there, this has been by far the most helpful information on the internet in my searches so far!!

There is aot of info here which I am taking in, but I’d be grateful if you could advise me..:

I am doing a van conversion and have an unfinished shower room. The walls are made of ply. Rather than sticking pvc on top and sealing all joins, which could add a lot of weight and cost, I would like to find the best way to waterproof the ply itself. This way the seals and corners stay visible in case of spotting and fixing future leaky troubles. My budget is small… Is linseed oil enough to waterproof my tiny ply box 55cm base shower room? I have a window in there for ventilation but I am also concerned that certain products could release harmful chemical fumes into my tiny home.

Thanks for your help x

Alan Howard
2 months ago

Hi.. I’m putting a skirting board and tongue and groove on the back wall of my bathroom where the lavatory is. I guess I need to seal it but wanted to paint it white using regular silk paint to match the rest of the room. Can you paint over stain sealants?

Charesse Hicks
2 months ago

Thank you, William for the great information! I am going to convert a gorgeous antique dresser that my mom refinished about 50 years ago. It was in my grandmother’s boarding house for a good 40 years prior! Because it was refinished 50 years ago and has had Pledge applied occasionally over the years, do I still need to lightly sand the wood before applying whichever sealer I choose to use? Also, I thought I might put a sheet of plexiglass over the wood. I am using a raised vessel sink on this piece.
Thank you for any advise you can offer!
Charesse

Charesse Hicks
Reply to  William Stewart
1 month ago

Thank you so very much for the information!

Samantha
4 months ago

This is brilliant! I’ve recently bought a corona pine sideboard to go into my bathroom to be converted into a vanity with a sink. I’ve bought a countertop sink to go on top. What do think would be the best product to use to make it waterproof and if possible, can you recommend one, please

Thanks
Sam

Dorota
5 months ago

Hi, brilliant article!
I was wondering if I could get your opinion on exposed bathrooms beams?
We exposed the old roof beams in the bathrooms in our renovation project (16th century cottage).
Is it best to leave them alone or protect with something? If so what do you think will be best?
we want to keep them looking as natural and authentic as possible?

Thanks

Dorota

Chloe
9 months ago

Thank you for this excellent webpage. I have an oak vanity worktop in my bathroom that I have sanded down ready to seal. I would like to stain it so thought I should go for the stain-sealer combo. However, I’ve noticed that the stain sealers you recommend (such as the readyseal) seem to be for exterior wood. Is that suitable for use in the home? Also, if I wanted to go belt and braces, could I use a varnish after it? Many thanks for your help

Shannon Lee-Rutherford
10 months ago

Hi there – the timing on this article is perfect. I have two mosaics on furniture grade plywood that I would like to hang in bathrooms. One of the mosaics is grouted, one is not (tesserae style). Do you have any suggestions on how to prepare the wood to resist the fluctuations in temperature and moisture in a bathroom? Thanks for your help,
Shannon

Emily
10 months ago

Really helpful article- thanks so much!

Is there a particular brand of sealant you would recommend for protecting a window that inside a shower?

Any recommendations would be gratefully received!

Thanks!

Jo T
Reply to  William Stewart
10 months ago

This is such a great page- thanks! I have a similar scenario where I have an exposed wooden beam and wooden panelling above the shower so they get steam & some splashback. Would you also recommend Polyurethane for this?
I’m not sure where best to use varnish like yacht oil vs an outside wood oil vs hardwax oil! I should add this is for the UK/European product rather than US in case you know if specific products.
Thanks so much!
Jo

Jo T
Reply to  Jo T
10 months ago

I should add – it’s a soft wood like pine.

Ron
10 months ago

Hi Mr. Stewart:
I am converting and old trundle style sewing machine to a powder room vanity.
I will be using a vessel sink.
The wood is dry but not cracked.
I think epoxy would be best, but how can I ensure the beauty of the gold oak is brought back?
I have used Boiled Linseed Oil for many years and am comfortable with it.
Can I use BLO to bring back the colour before applying epoxy?
Thanks.

Josie
10 months ago

I am building a log home and I want to keep 2 of the log walls in the bathroom natural logs. What would be the best wood sealer to use to waterproof them? The logs are pine, and smooth.
Thank you

Josie
Reply to  Josie
10 months ago

it’s brand new wood 🙂

Josie
Reply to  William Stewart
10 months ago

Thank you

Laura
11 months ago

Hello William this was very interesting ,thanks.

I am buying a vanity made by engenering wood and I will be adding a sink on top for my bathroom. Do you recoment this type of wood for bathroom and if so what varnish/oil/seal should I use to protect it from water spil and humidity ?
Also what type of wood do you recomend the most for bathroom vanities
Many thanks in advance

Andrew Cooke
1 year ago

Hi William,

Nice article but I’m still unsure what method to use for my bathroom.

I have some reclaimed wood panels to use around a bath.
I was going to stain them and then apply some teak oil over the stain.

I was reading about teak oil and teak sealant.
What is the difference and would I need to use both?

Also, can I mix the stain with the oil/sealant?

Thank in advance.

Andrew Cooke
Reply to  William Stewart
1 year ago

Thanks William, but what if I don’t want the finish to be glossy?

Katherine Roopchand
1 year ago

Can you recommend a good Stain – sealant product. I will be using it on a bath panel

Teresa
1 year ago

Hi William

We are up cycling an old pine sideboard which has already been painted into a vanity unit in a cloakroom (no shower or bath).
As the basin is only for washing hands how can we protect the painted work surface from water drips? The paint used on it is from B&Q home range furniture paint in a satin finish. Will two or three coats of this be enough or will we need some other sort of water sealant as well?

We did think we would need to buy a new waterproof worktop for the sideboard but someone said we didn’t really need to, any advice would be greatly appreciated. Thanks in advance

Teresa
Reply to  William Stewart
1 year ago

Thank you very much for the advice.

Reya
1 year ago

I’ve been searching for months how to waterproof wood safely for my shower walls. In person everyone says “no” and the internet is all over the board. I’m chemically sensitive as well, so I need to use something that is low or no VOCs AFTER curing. I have no problem working with a respirator, good airflow and even outside if curing needs sunlight. I don’t mind waiting hours, days or even weeks for the method to fully cure. There will also be an excellent air vent in the shower. So my question is; Is there a way to truly waterproof wood well in enough for inside a steamy shower? And if so, what to use and how to do so with little to no VOCs after curing? Thank you for your insight!

Reya
Reply to  William Stewart
1 year ago

Excellent! Epoxy is exactly what I was thinking about using! Thank you so much!

Sandi
1 year ago

Super helpful article, thank you! I’ve got a new teak bathroom vanity. The manufacturer recommends a clear matte varnish. Is it ok to just do the outside of the unit and the inside of the drawers, or should I also do the inside of the cabinet that won’t really be subjected to any water contact?

Adam
1 year ago

Hey William. I want to purchase a bamboo bench to put in my shower. It says its waterproofed already but I’ve read reviews on it where customers stated mold started growing. Is there a product I can use to waterproof it to prevent mold and mildew growing on it?

Mallow Robinson
1 year ago

William, I’m new at all this and very confused. I have an unfinished butcher block wood surround that absolutely needs to be waterproof. It also needs to be stained. Do I stain, use tung oil (and how much vinegar do I add?), General Finishes Topcoat after staining? Can you give me a “first do this, then this” answer? And product info would be really appreciated. Thank you.

Ginger
1 year ago

I have Thompsons wood sealant. Will that be sufficient???

Stacy
1 year ago

Hi there! I just saw this article! 🙂 Super great. Question – I have made a 10′ red oak vanity, I would like to add a little stain color to it, but need it waterproofed since the sinks/faucets will sit on it. I was trying to sort through all your comments, but got a little confused as to which would be best? Thanks in advance!!

Sheila Nelson
1 year ago

Hi I am doing a van conversion and using tongue and groove pine ceiling in the van. I would like to run the ceiling across the whole van and was wondering how to seal it so it works for the roof of the shower as well.

Thanks
Sheila

Nicole
1 year ago

Hi there,

I’m renovating my bathroom and want to make a natural wood panel look for the drop in tub skirt. What would you recommend we seal it with so it doesn’t accumulate drip stains over time? (Some one has told me to use yacht varnish)
Also would you be able to recommend a type of wood that would work best for
this?

Cheers,
Nicole

Pam Neitzke
1 year ago

Hi William I am putting in a pine toung and groove ascent wall in my bathroom. Will not be in direct contact with water but moisture from the shower. Can I use tung oil to protect the wood?

Emma Loofe
1 year ago

I currently have 2 large floating vanity shelves. They are oak. They were custom made and came ready to be installed. I want to if possible, sand them down as they have yellowed and I want a much more “chalked” paler look. Can you advise me on what to use to achieve this???

Marnie
1 year ago

We’re doing a loft conversion and an exposed overhead wooden beam will be directly within the showering area in the en-suite. What’s the best way to protect a structural beam from the water and steam? Many thanks

Daniela
1 year ago

William thank you for the excellent article. I’m turning an antique desk into a vanity with a vessel sink. The desk has a Birdeye maple veneer top that has some cracking which I don’t mind. I would like to protect the veneer against heavy water exposure. Would you suggest an epoxy?

Pam
1 year ago

I have a vanity made out of coachwood, at the moment the cabinet maker used organoil , I have applied at least 4 coats and the slightest drop of water leaves a mark, could you recommend anything better to use please.

Kristin C
1 year ago

What would you recommend for a child sensory/water table made from pine that would be exposed to water, things with food coloring, etc to prevent water damage and staining from the food coloring?

randy carpenter
1 year ago

I was planning to use sascho symphony to seal the logs in my bathroom. It is a water based product. Will this work and if so, how many coats should I apply?

Saurabh Gupta
1 year ago

Hi William

Would spray coating a bathroom door with a NC paint be advisable

Joyce
1 year ago

I stained a bathroom vanity and then used Varathane on it. After doing so I realized that will not produce a waterproof surface. What can I do now to make this surface waterproof? Do I have to and off the finish before using a sealer or other product to make it waterproof.

Rod
1 year ago

Can you use both the tung oil and the stain sealant on bathroom countertops?

Kim
1 year ago

Hi William I am in the process of doing a Shiplap wall in my bathroom I want to make sure no moisture or mold get into it i also put along top of shower , not sure what to use for the gaps and ends of wood .. I want to stain it and waterproof it not sure what is best to use .. thanks

Mandy
1 year ago

Hi William
We have fitted a countertop basin to an old pine dresser in our bathroom and have decided to tile the top as it’s already becoming water marked but how should we protect the surrounding wood which we’ve already waxed a couple of times
Thanks very much
Mandy

Mark
1 year ago

Hi William
I am making a tongue and groove bath panel set. I would like a driftwood sort of colour, what would you recommend that is also waterproof as the wood, would be direct on the floor which does get wet.

Arielle
1 year ago

I am making a jumbo pegboard shelf for my bathroom what would you recommend to seal the insides of the holes for the pegs and the edges? What brands too? Thanks for the help.

Ken Bryer
1 year ago

hello William,
Your article and comments are helpful and insightful. We have an oak worktop in the kitchen with the sink fitted into it, and the tap projects through the wood. I have finished with Osmo oil, which claims to be for worktops, but after only a short time the wood under the tap starts to go black and I have to sand down and start again. Is there anything more durable to resist the constant drip of water when wet hands operate the tap? Your advice would be much appreciated.

Mary Kay
1 year ago

Hi William-we are making thick mahogany shelves for our large walk-in shower. They will be hung from the ceiling.They will be in high humidity but not direct water. What is the best finish to use? Thanks!

Nina
1 year ago

Hello William,
Your post is very informative. I am purchasing a folding shower seat either made with walnut wood or finish(not sure). The seller says that it does not need to be sealed. How do i protect it from mold and mildew. after reading through your blog, I found boiled linseed oil at home depot. Will this do and keep the shower bench from rot, mold and mildew and water-proofed. What other steps I can take to ensure that the bench last s longer without any issues down the road. Advice is appreciated. Thanks!

Patrick
1 year ago

Hi William,

I plan on turning my laundry into a bathroom, now my problem is the shower will be within the window and worried the wooden frame of the window will rot in time when it gets wet. Is there a way to protect the wood with another layer of waterproofing? The frame already has paint on it too.

Your feedback would be appreciated. Thank you.

Kay
1 year ago

Hi William,
I’ve had to purchase a “ready to paint” bath panel which I want to paint with colour matched paint to the vanity. The vanity is an eggshell finish so what would you recommend I use to seal the bath panel to ensure I have a similar finish

Rachael M
1 year ago

Hey William,

We are making a cabinet for a bathroom that is made of both solid wood and plywood. We wanted to stain it espresso. After reading your great article I wanted to find a stain/sealer combo but I am really struggling to find an interior one. I’ve mostly come across exterior ones. Is this too excessive for the project? What stain/sealer would you recommend? Thank you!

Annette van Brakel
1 year ago

Hi William,
I have inherited an late 19th C, early 20th century Swedish kitchen chair. I would like to use it in the corner of a large bathroom. We have mechanical fan above the glassed in shower cubicle and a window that can open next to the bathtub. It is safe to keep this chair in a bathroom? Is it suitable for oiling? Does beeswax count as oiling? TIA, Annette

Abhishant
2 years ago

Hello William!
I want to make wooden pots so I will have to protect it from both water and soil. Will the above mentioned methods be enough to do the job or do I have to do something additional?
please help!

Gwennor
2 years ago

Hi William
We are restoring an old pine plank wood floor in our bathroom and were wondering what finish we should use? The planks have tar in them which will be sanded off. They are very old pine (maybe over a 100 years old.) We are especially concerned about protection from water as there is a big cast iron bath in the middle of the bathroom plus a relatively low level shower. Plus we need something to protect against slippage. Thank you for your suggestions. Gwennor

Misty Wylie
Reply to  William Stewart
1 year ago

Hi William, I have an addition to this question. We too are trying to restore the old wood floor in our house. We also believe it to pine. You answered everything we need to know about this (much appreciated, you are so great about answering all of these questions), except our situation goes one step further. Our situation is that with pets. We live with my mother in law and she has an unhealthy amount of pets, plus we brought our 2 dogs, which added to her 2 dogs, 4 cats and 1 pigeon (that’s right, i said a pigeon, aka sky rat, aka sharp pooper aka what the…..). Any way, is there a way to prepare the floor from pet waste? Also, would that be different from what we would use in the living room? Thank you in advance for your patience and kindness as will as for your shared knowledge.
Thanks again,
Misty

Sue
2 years ago

Hi
Thanks for your helpful article on sealing wood. Please advise!
I have a French Polished piece of furniture and have tried boat varnish but it didn’t dry hard and left marks when someone left a heavy object on top. That seems to be the case wit polyurethane too, which also didn’t go over the edges of the boat varnish, even though sanded down, and left a silver ‘scratch’. What can I use on French polish for a heavy-wear bathroom sink unit?

Jeremy
2 years ago

Hi William, We are installing IPE as the shower floor in our bathroom. Yup… we’re going for it. Essentialy the IPE will be our shower drain. So direct water on a daily basis. Thoughts on approach for sealing this? Any other advise.

Barry
2 years ago

Hi William,

1. We have a beech live edge slab we want to use as a bathroom vanity top( no shower/bath), what do you recommend to finish with that is low sheen and natural?

2. We have rough sawn plank pine flooring, again what would you recommend as a finish? This is in a cottage type house so want a rustic natural look. I’d prefer a quick dry solution as we don’t have an alternative living space for a long period of drying time.

Thank you and appreciate any guidance you can provide.

Sean
2 years ago

Thanks William, makes sense. And how long would you say it roughly take for the tung oil to dry before I can think about applying the sealant?

Best,

Sean

Viet
2 years ago

Hi William,

I am building a bathroom vanity using walnut plywood. What do you suggest to finish the wood without making it look glossy. Is Danish Oil sufficient to waterproof the vanity for this case?

Thanks

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