Results 1 to 12 of 12

Thread: Removing old Poly and Paint

  1. #1

    Removing old Poly and Paint

    So I own an 100 year old house, with most of the trim "intact". All the trim on the first floor has been recently painted over the existing polyurethane, all the trim in the second and third floors has a coat of what I assume is polyurethane. I do not believe most of the paint has lead, though there are a few places with lead paint, nor do I think there is lead in the polyurethane/varnish on the second floor.

    The trim itself is primarily baseboards with a nice ogee at the top, and casements, which are 3/4" boards with rounded corners. There are no beads or other adornments on the casements.

    Currently I have a 8" jointer with a helical head, and a 12" dewalt lunch box jointer. I could easily see buying a drum sander, or a more powerful planer if that was going to save me some time, since I'm thinking about doing most of the house. Same with buying/building a IR paint stripper. I've used chemical strippers in the past, and they're too much work, take way to long.

    I'd like to be able to preserve the original wood, maybe restain to a darker color, and apply a new coat of poly.

    What is the most efficient way to strip the paint and poly off these boards with a minimum amount of damage/material removed?

  2. #2
    If the woodwork is that old it will be an old fashion varnish. Poly is a more recent product. Still removing the finish is going to be so labor intensive it might be easier to remove all the woodwork and replace it. Not long ago the government was kind enough to ban the methylene chloride which makes removers doable to the DIY. The removers on the market today are more than double in price and takes ten times the labor to use.

    If you think you are going to strip the finish with a jointer and planer, that is really not an option. The finish will dull the knives so fast you will be constantly changing knives. You could run a 8' piece of trim once through a planer with paint on it and you could tell the difference in the knives by the time it reached the other end. The cost of the knives would be more than the wood is worth.

  3. #3
    Yeah, I figured the easiest option was to replace, but the grain is so tight on some of this old growth pine it would be a shame.

    What about the drum sander?

  4. #4
    Quote Originally Posted by Andrew More View Post
    Yeah, I figured the easiest option was to replace, but the grain is so tight on some of this old growth pine it would be a shame.

    What about the drum sander?
    Using a drum sander the paint and finish would gum up on the paper where you would end up spending a lot of time picking big chunks of it off the regular paper. It would be beyond using a sanding belt cleaner. If you can remove the woodwork from the house there might be a way to strip it. You might make a trough by splitting a piece of pvc pipe in two. Then mix a solution of sodium hydroxide and water. Make it very concentrated and would work better if it could be heated. You stick the wood in the solution for 2-3 hours and take it out and rinse it off with a power washer. It's what a lot of furniture refinishers used as a "Dip Tank". It works very well but if you are not careful what you put in it you can ruin the wood. If anything was veneered or plywood it would delaminate. Oak or ash would turn green to black and cause the grain to crack open but the conifer woods would strip fine with no damage. I used to dip stain glass windows for an antique dealer. It would strip multiple coats of paint off completely clean. It has to be thoroughly rinsed off though or will develop a white powder from the lye. It also helped to be washed with vinegar to neutralize it.

  5. #5
    Join Date
    Feb 2014
    Location
    Lake Gaston, Henrico, NC
    Posts
    4,053
    Supplied air hood, heat gun, and variety of scrapers. I have one of those big IR paint strippers, but we find the heat gun to be almost as fast, and with a lot better control.

  6. #6
    Could of interesting ideas. Edward, is there a good suggestion on how to heat the solution for the dip tank. Also what's the ratio of water to sodium hydroxide?

    I've got a heat gun, maybe I'll give it a try.

  7. #7
    Join Date
    Feb 2014
    Location
    Lake Gaston, Henrico, NC
    Posts
    4,053
    A painters 5 in 1 tool, with a comfortable handle, is a good tool for a lot of heat gun removal. Soften an area with the heat gun, and push the tool, rolling up the coating.

    The big IR heater works good on ceilings, but it's a two man job. One to hold the heater, and the other to push the softened stuff off. That's the only place ours gets used now.

    We use a small air conditioner as the air supply to the "disposable" Tyvek hoods. Long Shop Vac hoses, not used for anything else, transfer the breathing air from the supply to the hood, so the supply can be in clean air.
    Attached Images Attached Images

  8. #8
    Quote Originally Posted by Andrew More View Post
    Could of interesting ideas. Edward, is there a good suggestion on how to heat the solution for the dip tank. Also what's the ratio of water to sodium hydroxide?

    I've got a heat gun, maybe I'll give it a try.
    The sodium hydroxide could vary from company to company and I don't remember what brand I used. I had a tank that was 4'x10'x4' high which I kept 3 1/2' of the caustic soda solution in it. That would be 140 cubic feet of water which I used 4-80lb bags of sodium hydroxide in it. As far as heating it we more often than not didn't heat it in summer. It took so long to heat the tank we just used the heater in winter. A shallow tank like I described you could use a livestock tank heater as long as it didn't make contact with the PVC where it would burn through. You might try to find a used one cheap somewhere. I don't know long it would last in a caustic soda tank. The tank we used was made of stainless steel because it would eat up other metals.

    Keep in mind that caustic soda is a type of salt and when you rinse it the run off can kill grass or plants.

  9. #9
    How does the sodium hydroxide react to concrete? Occurs to me that might be a better "cheap" material to make a tank out of.

  10. #10
    I've never seen sodium hydroxide damage concrete but then I've never seen it used as a tank for a lye solution either. It would probably work but would be harder to get rid of when you are done with it.

  11. #11
    Quote Originally Posted by Edward Dyas View Post
    I've never seen sodium hydroxide damage concrete but then I've never seen it used as a tank for a lye solution either. It would probably work but would be harder to get rid of when you are done with it.
    I was thinking a smaller tank, so I could bust it up with a sledge hammer and dump it into the trash.

  12. #12
    Quote Originally Posted by Andrew More View Post
    I was thinking a smaller tank, so I could bust it up with a sledge hammer and dump it into the trash.
    For a single project I think what you have planned will work fine. Sodium Hydroxide is a type of salt. My experience with it is what was spilled on the concrete floor in my shop. All it really did is clean the floor. Better get after the project soon, it's certainly not a winter sport.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •