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  • Finishing techniques for baltic birch

    In the new year I'll be taking on an ambitious and rather expensive project, which will include a baltic birch plywood baffle. The end grain of the plywood is to be visible and used as a visual accent, both around the edge of the speaker and a slot port at the bottom.

    I intend to do a few tests on the plywood once I have it in hand, but I am wondering what others have done for finish on baltic birch? I am contemplating whether it's worth it to finish the bare wood, or apply a veneer. Has anyone stained or dyed this stuff with great success? I recently tried a gel stain on oak veneer and was very happy with the result, but obviously is a lot different material than this.

    Thanks for your thoughts. I've included a model of the speaker, the baffle will be the only bare wood bit, the rest of the cab will be finished with Duratex. The accent in the middle is also still up in the air, just something I was throwing around as an idea, to cut a dado and fill with coloured epoxy.

    Click image for larger version

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    I'm not deaf, I'm just not listening!

  • #2
    Re: Finishing techniques for baltic birch

    I've used transtint on two projects and both came out well. Lacquered over it for protection.

    Crappy pics of a sub build -
    http://www.avsforum.com/forum/155-di...al-18-a-3.html

    Soundbar I just did with exact same materials -
    http://techtalk.parts-express.com/sh...Soundbar/page3
    Builds - C-Killa - Speedsters - LithMTM - Talking Sticks - Pocket Rockets - Khanspires - Dayton RS Center - RS225/28A - Kairos - Adelphos - SEOS TD12X - Dayton 8 - Needles - 871S - eD6c - Overnight Sensations - Tritrix (ported) - Lineup F4 - Stentorians - The Cheapies - Tub Thumpers - Barbells - Tuba HT - Numerous subwoofers - probably missing a few...... :p

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    • #3
      Re: Finishing techniques for baltic birch

      I copied this design on the cheap. I remembered how nice this end grain BB looked just clear coated.

      http://www.hififorum.nu/forum/topic....TOPIC_ID=40179

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      • #4
        Re: Finishing techniques for baltic birch

        BB is rather bland, not much figure or grain to enhance so special techniques to enhance appearance are most often wasted. There are occasional examples of pieces which show some flash, but they are rare ime.

        If adding color watch the edges, half the plies will be end grain which will absorb more color and will highten the contrast of the "stripes". Sometimes turning almost black with dark colors.
        Gel stain is a good choice to minimize uneven absorption on the end grain. Applying a wash coat of dilute shellac also works well. Sanding to one or two grits finer than normal can also help a lot. As always, test first.

        Topcoat can be whatever is compatible with the coloring medium.
        ~99%
        Make me an angel that flies from Montgomery
        Make me a poster of an old rodeo
        Just give me one thing that I can hold on to
        To believe in this livin' is just a hard way to go

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        • #5
          Re: Finishing techniques for baltic birch

          Birch can be hard to get an even color on and can turn out blotchy. I also don't personally like the grain, so I would probably veneer the faces of the panels. You could still leave the end grain exposed so you can see the layers if you wanted.
          -Kerry

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          • #6
            Re: Finishing techniques for baltic birch

            Yeah, that's where gel stain and shellac come in handy.
            Very dilute shellac does a good job evening out the blotches used under normal oil/wb stains and sometimes dyes, gel stain does not absorb as much as it sits on the wood so again helps control the blotching by not penetrating much.

            Likewise on the appearance, most of it is rather too bland but can be chaotic when color is applied.

            Originally posted by Navy Guy View Post
            Birch can be hard to get an even color on and can turn out blotchy. I also don't personally like the grain, so I would probably veneer the faces of the panels. You could still leave the end grain exposed so you can see the layers if you wanted.
            ~99%
            Make me an angel that flies from Montgomery
            Make me a poster of an old rodeo
            Just give me one thing that I can hold on to
            To believe in this livin' is just a hard way to go

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            • #7
              Re: Finishing techniques for baltic birch

              Thanks for the tips everyone. I've read with stain that the key to avoiding blotchy finish is to ensure the piece is completely saturated, wither using gel stain or not.

              I think that I may be leaning towards a veneer on top. I was trying to avoid veneer as I have no veneering experience and would rather not test my luck on something like this. However, since the baffles are being CNC cut, it may be easy to apply the veneer before the CNC work, rather than have to trim around cutouts and edges after the fact.
              I'm not deaf, I'm just not listening!

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              • #8
                Re: Finishing techniques for baltic birch

                Originally posted by Navy Guy View Post
                Birch can be hard to get an even color on and can turn out blotchy. I also don't personally like the grain, so I would probably veneer the faces of the panels. You could still leave the end grain exposed so you can see the layers if you wanted.
                This has been my experience as well, it comes out blotchy and the grain is kinda rough. I did get the blotchiness to even out a little by sanding to 320 then wiping a thin coat of BLO over it before I put die stain on it (diestain thinned with water is what I used). I only worked a few test pieces before I gave up on the BB and decided to use something else. Oak takes stain very well, especially when compared to BB. I've never tried Bob's shellac method before but you still can't get around the grain.

                Edit: just read your response. Even using BLO and multiple saturating coats of the die stain I still had some mild blotchiness.
                "The ability of any system to produce exceptional sound will be limited mainly by the capability of the speakers" Jim Salk
                "Audio is surely a journey full of revelations as you go" JasonP

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                • #9
                  Re: Finishing techniques for baltic birch

                  If you have a wood that tends to be splotchy when stained, you need to use some kind of sealant or washcoat first. Dewaxed shellac can work, and there are products meant for that as well. An example: http://www.minwax.com/wood-products/...od-conditioner

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                  • #10
                    Re: Finishing techniques for baltic birch

                    Maybe no stain? I also had a project with BB and black duratex. I just finished the BB with wipe-on gel poly and it did not result in any blotchiness. The grain pattern came out quite nicely IMO.

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                    • #11
                      Re: Finishing techniques for baltic birch

                      Just have your CNC guy use a veneered plywood. It's cheaper than buying the veneer and plywood separate and much easier. I CNC veneered ply all the time with good results.

                      Originally posted by dcibel View Post
                      Thanks for the tips everyone. I've read with stain that the key to avoiding blotchy finish is to ensure the piece is completely saturated, wither using gel stain or not.

                      I think that I may be leaning towards a veneer on top. I was trying to avoid veneer as I have no veneering experience and would rather not test my luck on something like this. However, since the baffles are being CNC cut, it may be easy to apply the veneer before the CNC work, rather than have to trim around cutouts and edges after the fact.
                      Melby Audio - Flat Pack Speaker Kits

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                      • #12
                        Re: Finishing techniques for baltic birch

                        I agree that finishing baltic birch ply is problematic as it does not respond well to standard methods for hardwood. I also have the subjective opinion that many amateur woodworkers tend to do what I would call "overfinish" their enclosure, meaning too much stain/poly/lacquer. The approach I personally prefer is that used by Troels Gravesen. In his words:

                        For finishing the Baltic birch panels I use synthetic lacquer applied with a roller. Gloss 25 is used, semi-matt. Usually two coatings will do with in between sanding (grade 120-180).
                        I sometimes add the 1st coat before the final cutting. This reduce edge ripping as the outer veneer of Baltic birch is rather thin, unfortunately.
                        Action speaks louder than words but not nearly as often. -- Mark Twain

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                        • #13
                          Re: Finishing techniques for baltic birch

                          Originally posted by jclin4 View Post
                          Maybe no stain? I also had a project with BB and black duratex. I just finished the BB with wipe-on gel poly and it did not result in any blotchiness. The grain pattern came out quite nicely IMO.

                          [ATTACH=CONFIG]52720[/ATTACH][ATTACH=CONFIG]52721[/ATTACH]
                          That's actually very similar to what I'd end up with, thanks for that photo it helps a lot.
                          I'm not deaf, I'm just not listening!

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                          • #14
                            Re: Finishing techniques for baltic birch

                            Originally posted by Melby Audio View Post
                            Just have your CNC guy use a veneered plywood. It's cheaper than buying the veneer and plywood separate and much easier. I CNC veneered ply all the time with good results.
                            I had chose the baltic birch to guarantee a void free edge. My local wood shop does sell pre-veneered plywood, but not at 1" so I'd have to laminate two sheets together to get the thickness I'm after, or go down to a 3/4" board. I'd also have to inspect the pre-veneered boards to see how void-free they are. I'd rather not have to fill voids on the edges after I get the CNC work completed.

                            [edit: another thought is I could buy a thin 1/4" sheet of pre-veneered board and laminate to a 3/4" baltic birch board.]
                            I'm not deaf, I'm just not listening!

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                            • #15
                              Re: Finishing techniques for baltic birch

                              That looks more like cabinet grade face than typical Baltic Biirch, which is normally a lower grade face.
                              It's quite nice looking.

                              Originally posted by dcibel View Post
                              That's actually very similar to what I'd end up with, thanks for that photo it helps a lot.
                              ~99%
                              Make me an angel that flies from Montgomery
                              Make me a poster of an old rodeo
                              Just give me one thing that I can hold on to
                              To believe in this livin' is just a hard way to go

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