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ssullivan 01-04-2006 14:09

How to refinish a plywood floor?
Anybody have any tips for someone who can't finish a floor to save his life? :confused:

Here's the background:

We did not go for teak and holly. We did not go for traditional at all. I have a faced plywood with a dark stain over it. Looked great when I started applying the polyurethane. Now it looks like crap.

I seem to get small bubbles here and there that don't go away while it's drying. These bubbles make craters in the surface. That's the first problem.

Second, I have little "nibs" or raised things that appear to be from the grain of the wood (I used a wood sealer prior to staining)

Third... I set up a "workshop" in the cockpit to try and do this where it's warm and where I can control moisture, etc... It's in a full cockpit enclosure. Stupid me... the cockpit is pitched, so now, on my 3rd coat, I have pools of urethane making "hills" in the wood.

I'm about to throw these f*ckers right into the drink!! :)


1) Can I save these pieces I've already done by sanding out the "hills"?

2) Anyone have any smart techniques for finishing wood when they live aboard and are doing a cabin sole?

ssullivan 01-04-2006 14:37

You know what? Forget urethane jobs....
"I Need To Barter... Want a Free Yacht Charter? (NY/CT/RI)"

I'll give a free charter to anyone who can make my urethane job look professional.Here's what you get:
4 days / 3 nights aboard this yacht:
The going rate for this vacation would be $2800 if you look at our rates page. You get it for free if you can help us get the urethane job right!
You can have this vacation this summer, any time you want in Long Island, CT, or RI.
I'm looking for someone to apply urethane to approx a dozen wooden panels I have already cut, applied wood sealer to, and stained. I just need someone with a shop around the NY/Long Island/CT area who can produce a gloss like a grand piano might have... super shine - no bubbles, nits, or any imperfections.
This vacation is all inclusive - meals, bicycles, etc... all the facilities of the yact are at your disposal, including the personal chef and personalized menus. Food included!
Any takers??
I could really use the help.

Kai Nui 01-04-2006 15:20

Great deal for someone Sean. Sorry I can't get out there right now, or I would go for it. Best of luck. Bright side is, most people would have needed help many projects ago. If this is the worst you have to deal with, you are ahead of the game.
You might consider a local flooring company. The technic should be the same for the boat, as for residential flooring.

capt lar 01-04-2006 15:38

Yes, once the coat dries, you can sand down. Coats should be thin so no sags or puddles. Small bubbles are common. You just knock 'em down between coats. Last coat real thin. It is 90% prep and 10% application - three or four times around. My finisher just wrapped up 2400 s.f. oak job for me Friday. Took him 2 weeks.
One of the yards may have a brush guy that will go for the charter offer. May not be too many hardwood floor finishers out that way and, like most of the trades, more bad ones that good. Wish you were closer.
Hang in there.


Ram 01-04-2006 15:47

Sometimes if you breath on the bubbles that can pop them wile its still wet, I have seen a can of stuf, it may be co2 but im not sure that can be sprayed to get rid of the bubbles

Jentine 01-04-2006 15:47

Isn't frustration wonderful.
It brings out our humble side.
Sean, what polyurethane are you trying to apply?
Is it for floors or is it an exterior marine varnish?

Steve Kidson 01-04-2006 16:10

Finishing Floors
Polyurethane is a great product, but can be difficult to get a good result if not familiar with the product. I own a cbinetmaking and joinery business, and a number of our projects have a polyurethane painted finish. I offer the following as a summary of our experience and knowledge.
  • Ambient tempertaure while applying - check manufactures recommendations; you will find difficulty if too hot or cold.
  • Humidity - high humidity, as you may find in the marine environment, creates "humidity blisters" and/or clouding in the finish as it drys
  • Application is usually best done by spray in a booth with filteration and ventilation; this may not be possible in you situation
  • Dust and other airborne particles; polyurethane has a long "tack off" time where the surface will be vulnerable to particles settling onto the wet surface
  • As mentioned, preparation is the key; I myself hate sanding and prep work, but it is the major part of the work. Sure there is skill required to apply finish with an even coat, no drips, runs or dry spots, but a perfectly applied finish wil still look s#?t if surface is not well prepared.
In summary, if you can take floor pieces to a polisher or even an auto spray painter, you can be guaranteed a first class finish. I Australia, polyurthane finish costs me $AUD100 per square metre.

Hope this helps, and good luck.

Fair winds


Jentine 01-04-2006 16:50

I sent you a PM.

ssullivan 01-04-2006 17:07

Thanks for the replies... some very VERY good advice here, and I almost deleted this thread and started a new one. Why?

I have determined that this is the one project that is too much for me. I figure other people who do this professionally will have sprayers, workshops, and could whip this out in short order compared to the week or two of work I'd be facing doing it myself aboard the boat.

I'd much rather work my butt off for 4 days doing a free charter than spend all this time setting up the boat as a paint shop... only to probably make another error. I wasn't kidding... I do stink at this wood working stuff. :)

Thanks again folks.

Islandmike 01-04-2006 18:20

I have a 200 year old post and beam house in CT, with all wide plank floors. The only way to avoid bubbles is to use a foam brush and keep feathering it. All of my floors have come out like mirrors, and yes you can sand out your boo boos.

Mike - S/V Tivoli

Talbot 03-04-2006 03:26

Foam brush or even put on very thin with a cloth - works for Norm Abraham - if the ambient temp is hot, then I would thin anyway.

Alan Wheeler 03-04-2006 13:46

Sean, does that include the airfare??Nah just joking:D

Lets start back at the begining. So you sand the timber with your final grit. Usually a 120grit is fine. It's kinda one of those "experiance" things, but fine grits are better on softer timbers. Especially if they have little grain.The fine paper will bring out more grain definition. Fine papers on hard timbers will polish it too much and one, be harder for the finish to adhere to and two, darken the timber look.
The first thing to do after the last sand is to clean. A good vacum and then a tack rag over the entire surface. Ensure NO dust anywhere. Dust is your enemy. Dust baaaad.
OK, so the surface is now clean we will assume.
The first thing is paint preperation. If the paint is two pot, mix enough to do a coat. Allow it to stand once mixed for at least 15mins. This allows two things to happen. One, all air bubbles will rise out of the paint to some extent, ad two, the most important point, it starts a reaction creating "long chain molicules".
Now, even though it is a new can of paint, FILTER IT!!!! Get a paint filter to ensure small "blobs" are filtered out. Trust me, it happens.
The first coat is a sealer. It will cause the fibres in the grains to swell and stick up. This is normal and after the paint has dried, you do a light sand. Use a 240-280grit and go over very lightly. It is just to knock of the tops of those fibres. Do not cut the coating too much. Or the next coat will do the same thing.
Now using all the above, place down the number of coats you want. 3 minimum, 5 would be nice, anymore is a waste. Unless you have a dust particle or blenish, try not to cut between coats. Only cut the second to last coat. Use a very fine paper such as 320grit. Lightly sand to ensure you have a very smooth surface and then apply the final coat.

How do you apply?? OK, roll on a small area. Rolling ensures you have an even film coverage. Roll slowly, not to fast or you will create bubbles. Don't do too big an area at a time, or the paint will gel and the brush will leave marks. Use the brush to "lay off" the surface. Use the tip of the brush only and very lightly. Don't "Brush" it or you mark it. Always maintain a "wet edge". If possible, keep all edges over joins in timber. This stops them from being so noticable.

Ensure you are using a Brushable Urathane. Some are for spraying only. If you thin, make sure you thin with the recomended thinners and especially if it is a special brushing thinner. Do not over thin. Especially in a high humidity area. Humidity STOPS paint from drying properly, it doesn't speed it up. Unless you are using moisture cure paints. So adding thinners will slow drying and trap excess solvents and can cause problems in later coats. Most Urathanes, especaily two pot, DO NOT require thinning. Infact, what tends to stand a good paint out from a cheap one is the lack of solvent. Solvent can also reduce your gloss.
Ask away if I can help more.

ssullivan 06-04-2006 08:20

Thanks everyone. I have learned a lot about finishing the wood from this thread. I think I was only slightly off. However, I dropped the cabin sole in partially finished to get a look at it... and... it looks bad. Not due to the finish but due to the style. We need to go traditional. The boat had a mind of its own and decided to revert to traditional looks. I have posted a follow up in a new thread:

Alan Wheeler 06-04-2006 13:07

I replied in the other thread Sean. It's good to try and keep threads together if you can.
I noted that you said edges are damaged on the old panels. Can these edges be repaired? or covered with a new timber edging?

skipperaris 24-04-2006 12:10

I doubt it is any use to you Sean but it may be of general interest.

I had the same issue last year. My original plywood floor panels were faced with teak veneer with black lines running at 40 mm intervals.
It was all varnished.
Very nice when it was all new. But it was just varnished wood and therefore not very resistant to abrasion.
Every year I had to sand down the old varnish and put on a new coat. And every year some new deeper scratch would be added to the old ones until the look of it all was no longer acceptable. The varnish could only diguise so much...

So I was faced with the problem of what to do about it and like you, I considered a nice solid coat of paint but also like you, I do not feel confident of making a good job of it.

The final decision was to sand it all down and face it all with a synthetic material which is made for just this purpose.
It is melamine - some people call it formica - but I really don't care what the right term is.
It looks just like the original teak vaneer even to the point of having the grain on the surface which makes it very non-slip.

The difficulty with this is cutting the individual panels so that the black stripes will give the illusion of continuity and also sticking it on could be tricky. Ideally you need a large press for this.

A year later it is in the same condition as when first put on. No more sanding and varnishing for me.

If anyone else has the same floor problem I would recommend it.

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