Announcement

Collapse
No announcement yet.

Help with plywood subfloor problem

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Help with plywood subfloor problem

    Hello,

    I'm new here, and I signed up so I could ask for help with a problem.

    I tried to seal a plywood subfloor using shellac that I mixed with BioFlame denatured alcohol. I did a test patch outside, and it seemed to work fine. After applying the mixture to my floors (a bedroom about 11x17 feet), the smell of the BioFlame did not go away. I then tried to seal in the smell of the BioFlame with 5 coats of AFM Safecoat’s Polyurseal BP. This helped but the smell persisted above 68 degrees F and it gets much hotter than that during the summer.

    I then sanded off almost all of the Polyurseal BP and most of the shellac (the shellac is still present in the high spots of the plywood, and in the knots). However, the shellac/BioFlame seems to have soaked into the plywood even deeper since the smell of the BioFlame is still present, now even at 55 degrees F.

    I’m wondering

    1) if there is anything I can do to make the smell of the denatured alcohol dissipate once it is saturated in wood

    2) should I use a drum sander to more aggressively sand down the plywood

    I’ve already spent hundreds of dollars renting two sanders (a square buff and belt sander) plus the previous expense for the AFM Safecoat sealer. Plus, sanding and the ensuing wood dust is really awful, but I’ll do it again if it solves the problem. However, I don’t know how deep I need to sand to get rid of the solvent smell nor how much of a problem I might cause if I sand too deep into plywood.

    Also, it seems very odd to me that the Bioflame still smells so bad. I phoned Rechochem and the ‘customer service rep’ was rude and unhelpful.

    If pictures will help, let me know and I can post some. Thank you in advance.
  • Thread Continues Below...

  • #2

    Re: Help with plywood subfloor problem

    I wonder what's in Bioflame? Alcohol normally flashes off pretty fast. I would think a few warm days with lots of ventilation would get rid of any smell.

    What was the reason for wanting to seal the subfloor?

    Comment


    • #3

      Re: Help with plywood subfloor problem

      Yes, pics would be of appreciable interest for starters. Like drzaius, I ask the same question although it is partly irrelevant now, why?. But anyway, you apparently have 5 or 6 sheets installed (11 x 17) - how, e.g. what fasteners? nailed, stapled, screws,. adhesive...? If however, you find a need to sand the surface, I would think a rotary disk sander with a dust port to hook up to a vacuum would be a wiser and more appropriate choice. Also, maybe try calling the manufacturer back, we all have bad days. What about their web site? Look for the product's accompanying Data Sheets for information.

      Do you have a scrap that has been coated with all this alcohol based stuff? If so, try cutting a piece off the end to see how far the solution liquid has penetrated.

      Verify that and post some pics please and let's reconvene.

      P.S. What about pulling up the plywood if possible (fasteners?) and flipping it over. Is the smell too strong for that?
      Last edited by Woodwreck; 11-21-2018, 12:00 AM. Reason: typos, P.S.
      Start slow; wind down gracefuilly

      Comment


      • #4

        Re: Help with plywood subfloor problem

        Ethanol by nature is pretty much odorless. They add chemicals so it doesn’t taste very good and has a very strong odour. in camping fuel’s the chemical is burned off. If you let camping fuel’s evaporate (the ethanal which flashes off pretty fast) The bad smelling/testing chemical is left behind. This could take years to get rid of the smell. The reason I know this is, I did something similar with a window air-conditioning unit support, made from plywood. I pretty much soaked the plywood in end cut preserve, which I would watered down with just a little bit of Ethanol fuel . And if the floor gets wet and then a nice hot day again up comes the smell.

        The only thing I could probably suggest (but not with great confidence) would be kills primer. You might have to spray the bottom of the board or roller/brush it too. You might want to just roll a test bored up on a set of sawhorses in one room. You might hate the smell of that kills primer too.

        The for sure solution would be rip up the subfloor. It could be glued to the joists which really makes this, A little bigger of a job.
        Last edited by Matt Matt; 11-20-2018, 10:32 PM.
        nnieman likes this.
        For every action there is an equal and opposite reaction.
        Sir Isaac Newton.

        Comment


        • #5

          Re: Help with plywood subfloor problem

          The odor should hav gone by now. But, if it still persists, a layer of vapor barrier under the flooring should contain it.
          Me: How do you spell “apathy”?
          Reply: Who cares!

          Comment


          • #6

            Re: Help with plywood subfloor problem

            It may be a reaction with the plywood itself?? Try on a completely different plywood as a test.

            It may be easier to replace the plywood than trying to eliminate the smell.

            Talk to to your local suppliers about the issues. These do not have to be the ones the product was purchased from.
            Egon
            from
            The South Shore, Nova Scotia

            Comment

            • Thread Continues Below...

            • #7

              Re: Help with plywood subfloor problem

              Originally posted by Matt Matt View Post
              Ethanol by nature is pretty much odorless. They add chemicals so it doesn’t taste very good and has a very strong odour. in camping fuel’s the chemical is burned off. If you let camping fuel’s evaporate (the ethanal which flashes off pretty fast) The bad smelling/testing chemical is left behind. This could take years to get rid of the smell. The reason I know this is, I did something similar with a window air-conditioning unit support, made from plywood. I pretty much soaked the plywood in end cut preserve, which I would watered down with just a little bit of Ethanol fuel . And if the floor gets wet and then a nice hot day again up comes the smell.

              The only thing I could probably suggest (but not with great confidence) would be kills primer. You might have to spray the bottom of the board or roller/brush it too. You might want to just roll a test bored up on a set of sawhorses in one room. You might hate the smell of that kills primer too.

              The for sure solution would be rip up the subfloor. It could be glued to the joists which really makes this, A little bigger of a job.
              Killz primer is the way to go.

              I spent a few years working in disaster restoration/insurance jobs.

              https://www.homedepot.ca/en/home/p.o...000677388.html

              Nathan

              Comment


              • #8

                Re: Help with plywood subfloor problem

                My guess is that the "denaturing" component has an odor. An on line review I found said it smelled like nail polish remover when burning. I wonder if the denaturing component is Acetone?

                Comment


                • #9

                  Re: Help with plywood subfloor problem

                  The denaturing component is usually methyl hydrate (wood alcohol, methanol). I've used the Bioflame stuff quite a bit and it doesn't seem any different that the denatured alcohol I got from Lee Valley. I use it to make shellac as well as clean up and wiping of a surface before finishing. It evaporates much faster than mineral spirits.

                  As far as the smell problem. When something evaporates (flashes off) where does it go...into the air. If you have a large a room where you have put down a layer of shellac on the floor, then the smell will move from the finish to the air as the finish dries. If the room or house is sealed, where can the smell go. You have sealed the floor with the WB finish so the smell won't be coming from there. But now the room is filled with the alcohol fumes.

                  My advise ... a little late now. I would have just opened a window and let the smell out and some fresh air in. This is the same as finishing the inside of a drawer. Use shellac or a WB finish and you can put your clothes into it a couple of days later. Use an oil based finish and the smell will stay in the drawer for a few months.

                  If you want to reseal the floor, you can use Killz. It is going to have an odor of it's own as it is oil based. And oil smells tend to hang around longer than alcohol smells. Sooner or later, you will have to let some fresh air into the room.
                  the other Ken
                  ------
                  "Each flitch, each board, each plant can have only one ideal use. The woodworker, applying a thousand skills, must find that ideal use and then shape the wood to realize its true potential" - George Nakashima

                  Comment


                  • #10

                    Re: Help with plywood subfloor problem

                    I'm no chemist and won't speak to a remedy for the OP's situation. I have used Kilz, though. It's an excellent sealer but I think it's alcohol based as well.

                    Comment


                    • #11

                      Re: Help with plywood subfloor problem

                      Hello Everyone,

                      Thank you for all of your replies. I will try to answer your questions and reply to your comments as best I can:

                      1) we are sealing the floor because my daughter is reacting to something in the room (she has allergies). The plan was to do two coats of shellac to seal in any terpenes followed by two coats of AFM Safecoat to seal in any formaldehyde. We did not anticipate having a problem with the solvent. We have since learned that isopropyl alcohol would have been better but I had read that it should not be used with shellac due to its water content.

                      2) nails hold down the subfloor

                      3) we have been ventilating the room with fresh air for about 3 weeks

                      4) As far as a solution, we can't use Kilz (or BIN) as it would be much too strong for my daughter. This is why we chose to mix our own shellac.

                      5) Shellac, I have since learned, can leave its own smell. Google 'shellac smell won't go away' and you'll come across people who don't use it because of that exact problem

                      6) I don't think the smell in the room is from the shellac, though. I believe it is the BioFlame

                      7) I worry that Matt Matt is right and that the solvent smell won't go away as it has penetrated into the wood

                      8) we can't remove the plywood to either flip or replace due to location of walls. We could do this with 2 sheets only

                      9) I don't have the sample any longer (would have been a great idea to check the penetration level)

                      I've attached some pics. Some of the pictures show the floor before we sanded off the two coatings. Some of the pictures show how the high spots are resisting being sanded down. I first used a square buffer sander with 23 grit, then a belt sander with 36 grit (lowest I could find).

                      Given what you see in the pics, would a 'rotary disc sander' still be the best option? Is that an orbital or random orbit sander? This is all new to me--I've never dealt with sanding before. I realize that a drum sander is risky due to depth of plywood veneer and nails. I would try to either nail the nails in deeper or remove some of them. Still risky though....

                      I will try Rechochem (Bioflame manufacturer) again on Friday--it's a very busy week for me....

                      Thank you, everyone, again. I really appreciate it. We're (wife and I) pretty crushed that we ended up making a bad situation exponentially worse.
                      Attached Files

                      Comment

                      • Thread Continues Below...

                      • #12

                        Re: Help with plywood subfloor problem

                        Interesting...I just checked out the Info sheet about BioFlame (No MSDS online), and it says it is made of isopropyl and ethanol. So, there really should be no smell. I wonder if the smell is something else (the shellac?) or there is still some other ingredient that is not listed on their info sheet but on the MSDS. I will request an MSDS copy on Friday....

                        http://www.recochem.com/ca/media/upl...st_2017_EN.pdf

                        Comment


                        • #13

                          Re: Help with plywood subfloor problem

                          Now you come to bat with some good information/pictures. If I knew your situation for hand I would’ve suggested using a cheep water-based drywall primer/sealer. Home Depot Behr.

                          The only thing I can suggest now “especially” to make the old lady and little lady happy. Is full removal. You can sand it until there is an 1/8 of an inch left and then prime it and overlay it for strength. But if the boss of the house says she can still smell it you will go backwards again.

                          if you haven’t put on any expensive floor coverings, drop the Skil saw through the joist bays and remove and replace. You can go plywood for $50 a sheet or you can do OSB for $35 a sheet. Or maybe less depending on your area. I just pray for you, that construction adhesive hasn’t been dropped on the top of each joist.

                          For every action there is an equal and opposite reaction.
                          Sir Isaac Newton.

                          Comment


                          • #14

                            Re: Help with plywood subfloor problem

                            Before I did full removal, I would try covering the whole floor with 6ml poly, sealed at all edges with a good bead of sealant, e.g. acousta-seal. The smell is from off gassing, and if you seal the gassed up behind vapour barrier, surely you won't smell it any more, no?

                            The plastic vapour barrier could then be covered over cheaply with a nail free floating floor, e.g. click laminate.

                            Comment


                            • #15

                              Re: Help with plywood subfloor problem

                              Originally posted by callee View Post
                              Before I did full removal, I would try covering the whole floor with 6ml poly, sealed at all edges with a good bead of sealant, e.g. acousta-seal. The smell is from off gassing, and if you seal the gassed up behind vapour barrier, surely you won't smell it any more, no?

                              The plastic vapour barrier could then be covered over cheaply with a nail free floating floor, e.g. click laminate.
                              Ryan, I fully agree with you. But if your wife is anything like mine, this is like mold. My wife’s mind it won’t be clean regardless of test equipment. Her nose is the be-all and end-all.


                              For every action there is an equal and opposite reaction.
                              Sir Isaac Newton.

                              Comment

                              Working...
                              X