Remove Polyurethane Finish From Wood.

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
exostash
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Remove Polyurethane Finish From Wood.

Postby exostash » Mon Jul 06, 2020 8:58 pm

[A duplicate thread on identical topic has been merged with this thread—moderator.]

I have a 1985 Montauk with wooden trim. I have owned the boat since 1992. Several years ago I removed the wood trim and [applied a finish with polyurethane].

Some wood is exposed and is peeling. Some wood retains the finish.

I may remove the polyurethane finish, and then apply oil to the wood.

Is oiling the wood after removal of the polyurethane finish a good idea?

Tell me the best way to remove the polyurethane.

jimh
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Re: Remove Polyurethane Finish From Wood.

Postby jimh » Tue Jul 07, 2020 8:45 am

To remove a hard surface finish from wood the most likely method to be effective will be abrasion. Removal of a layer of wood will be an inevitable side effect.

The use of an oil finish is appropriate if the wood is Teak.

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Phil T
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Re: Remove Polyurethane Finish from Wood

Postby Phil T » Tue Jul 07, 2020 11:13 am

You will need to sand off the poly.

From the factory, mahogany was varnished and teak was oiled. You can go to either one or both.
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KARLOW
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Re: Remove Polyurethane Finish From Wood.

Postby KARLOW » Fri Jul 17, 2020 3:39 pm

[To remove a Polyurethane finish from wood use an unspecified] paint stripper [and] sand lightly. Use a hard plastic scrapper and green scrubbing pad. Wear safety gear and be very careful with the stripper.

jimh
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Re: Remove Polyurethane Finish From Wood.

Postby jimh » Sat Jul 18, 2020 10:05 am

Using caustic, harsh, toxic chemicals designed to remove paint on a Polyurethane finish on wood should be undertaken with caution. The outcome could be harmful to the wood and to the refinisher.

Vance's Revenge
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Re: Remove Polyurethane Finish From Wood.

Postby Vance's Revenge » Mon Jul 20, 2020 12:09 am

I just stripped and re-varnished the wood gunwales on my Revenge 22. I used Citristrip from Home Depot.

Put it on pretty thick with a cheap brush and cover it on a cool day or evening with 1 mil plastic so it doesn't dry out. I let it sit for about 2 hours on a cool morning and scraped it with a plastic scraper. Worked terrific and didn't have to do a ton of sanding.

If you need to, do several coats of the Citristrip procedure. It's not really a big deal.

To re-varnish I used Minwax pre-stain and then stained it with ZAR 120 Teak Natural stain. The stain is supposed to help keep the wood from bleaching out under the varnish. The varnish I chose on my second go around was Totalboat HALCYON amber gloss.

This is a water base varnish that is incredibly easy to use. It comes in a pouch with a spin on cap and just poor back in what you don't use. No stirring or anything. It dries for re-coat in as little as 1 hour so you can easily do 3 to 4 coats in one cool morning. I spent weeks with the oil based spar varnishes. Not quite as pretty and level as the Oil base Spar Varnish I have used in the past but the ease in comparison is close enough for me.

Be sure to completely surround the trim when you varnish it to seal it so water can't get under the varnish from any direction.

Good luck.

Vance

jimh
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Re: Remove Polyurethane Finish From Wood.

Postby jimh » Mon Jul 20, 2020 10:21 am

VANCE—thanks for your first-hand account of using the product CitruStrip which was purchased at Home Depot.

Did you use the Gel or the Paste version?

Were you removing a Polyurethane finish?

Vance's Revenge
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Re: Remove Polyurethane Finish From Wood.

Postby Vance's Revenge » Mon Jul 20, 2020 10:50 am

Hi Jim,

I used the gel that comes in a Jug. I didn't do the original finish the gunwales. It was there when I purchased the boat but was told by the previous owner that he did the coating with polyurethane.

The coating was in very poor condition and the Citristrip did a great job. Especially when I covered it with the plastic to keep it from drying out quickly.
I used the same process to remove topsides paint he had painted the floor with. I don't know the brand of Topsides paint he used but I put a coat of CitriStrip on it, covered it with plastic for a while and blew it off with a power washer. It removed the paint down to the original gel coat. If I remember correctly I had to do a couple coats in some spots.

The TotalBoat Halcyon is very weird but interesting. I comes out of the package like runny liquid peanut butter and dries clear. Seems to be very hard when dry. The water base is incredibly handy. I just ran it through a paint strainer into a paint cup, brushed it on and then dumped the left over back into the package with a small funnel. Rinsed the brush and cup and repeated in a little over an hour. 3 coats a day is easy. It will look best if you lightly sand it with 400 after about 3 coats then recoat.
I can't say how it lasts because I have only had it on the boat a few weeks. I plan to scuff it up annually and put a maintenance coat on all my hardwood. It says it can be coated over any type of varnish that is in good condition.

Vance