Need last minute veneer tips for my Pi speakers.

Discussion in 'Home Theater Projects' started by James W. Johnson, Jul 13, 2004.

  1. James W. Johnson

    James W. Johnson Screenwriter

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    Yeah so I have built a ton of subwoofers and a few speakers and have never had a successful veneer project...twice I have tried using some raw veneer from a local store and twice it has failed.
    I used contact cement both times and had bubbling both times.
    I have always resorted to paint or Formica laminate.


    Anways I am ready to finish my Pi speakers , the boxes are prepped and ready to get veneered.
    This time I ordered a few sheets of 10 Mil paperbacked veneer from Tape Ease in hopes I will be successful this time.

    I have read of a few of you guys that use glue and an iron but i'd rather use contact cement.

    Anyhow these are fairly big at ~ 30" x 14" x 18" so there
    is plenty of room for error. :)


    1. will I have issues with the veneer sticking to the PCV ports? They are perfectly flush with the baffle.

    2. Tape-Ease says that trimming is best done with a utlility knife ...last time I did trim this way and
    the wood splintered. / How long after applying should
    you trim? I always trim my laminate right away.

    Thats all for now..I expect to start veneering next weekend so I have several days to consider it and come up with a plan.

    I'd appreciate some tips or tricks on how to best tackle this job.

    The cabinets have been sanded down to 120 grit and were washed with water and a rag afterwards.

    [​IMG]
     
  2. GrahamT

    GrahamT Supporting Actor

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    Hi James,
    I use raw veneer and put wood glue on both the veneer and MDF. Then I let it dry and iron it on. It always turns out perfectly flat, and it is quick and easy. It dries instantly and if you have to make adjustments you can re-heat the the glue.

    To trim the extra I have tried a mat knife but I much prefer a flush trimming router bit. The corners turn out very nice.

    Hope this helps and hope you like the new speakers.
     
  3. Allen Ross

    Allen Ross Supporting Actor

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    what did you chose for Pis? how do you like them for music? (If you have played them yet.)
     
  4. Dave Poehlman

    Dave Poehlman Producer

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    I trim mine right away too with a utility knife (I don't own a router)... however, I try to trim from underneath the veneer. Once I've got it stuck on I turn the box over and lay the freshly veneered side down on a scrap piece of MDF. Using a sharp utility knife, I cut off the excess leaving a small overhang. This I then take off with some medium grit sandpaper. The sandpaper trick works for me because I once undercut the veneer which left a gap in the finished corner... looked bad. Or you could buy a router. [​IMG]

    One more tip to avoid bubbles, if you haven't been doing this already, is to curl the veneer parallel to the grain so it's a concave "U" shape and start sticking it on from the middle of the piece out to the sides. These aren't enormous pieces here, so you shouldn't need to do the "paintstick trick".
     
  5. Mitch N

    Mitch N Stunt Coordinator

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    Apply yellow wood glue to both substrates.

    Also apply some water from a spray bottle to the opposite side of the veneer. This will prevent curling of the veneer.

    allow to dry.

    place veneer on surface and you can tape into place or use push pins to secure into place.

    Use an old iron to iron on the veneer to the enclosure.


    To trim, using a very sharp blade like a utility knife with a new blade in it works for me. However face down the surface you want to cut, and cut against a hard surface. Or use a router [​IMG]
     
  6. Pete Mazz

    Pete Mazz Supporting Actor

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    Bubbles are usually caused by trapped air or not letting the contact dry enough and trapping the solvent gassing off. Either way, a pinho;e thru the veneer should fix it followed by some pressure with or w/o heat.

    General tips would be:
    Use a stipple roller cover made for contact cement.

    Buy spray-on contact if you can find it. It's thinner and rolls on much easier.

    Avoid over rolling. Once contact starts to tack up, it'll just make a mess.

    We used to pour the contact on a scrap piece of MDF and work it into the roller so as not to overload it. Cutting a piece to fit into an old 5 gallon pail and pouring the contact into it works great. Keep the lid on loosely in between coats.

    Better to apply a couple of thin coats to the substrate than one heavy one.

    I also think the water-based CC works well. They have made significant improvements to it in the last few years. You can use a cheap foam roller cover. Just make sure not to put it on too thin.

    A laminate trim bit in a router works fine, as long as it's sharp. Go slow when trimming cross-grain.


    Pete
     
  7. James W. Johnson

    James W. Johnson Screenwriter

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    Excellent tips guys, thanks..that will certainly help alot.
     
  8. James W. Johnson

    James W. Johnson Screenwriter

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    I chose the Stage 4 Pis...I cannot answer your second question yet. :)
     
  9. James W. Johnson

    James W. Johnson Screenwriter

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    Ok I am scared to use contact cement again after doing some reading at Woodweb's Veneer forum.

    I think I'd be more comfortable with some other method this time, also it would be nice to match the grain in a few spots and that would be nearly impossible with contact cement.

    The iron method concerns me because of the possibilty of separating the veneer from the paper backing.

    What other options do I have here?
     
  10. James W. Johnson

    James W. Johnson Screenwriter

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    I have mulled it over and have decided to go the old school method, yellow glue and weight.
    I am going to borrow a few hundred pounds of sand bags or cinderblocks to use as weight. Actually I'd like to aim for 300lbs worth of something..whichever takes up the least space. Id really feel safer with like 500lbs but I am not sure if that is realistic or not as far as being able to balance all of it on top.
     
  11. Pete Mazz

    Pete Mazz Supporting Actor

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    It doesn't take a lot of force to have it adhere. Biggest concern is equal pressure and panels that are not exactly flat. To solve both issues, lay a piece of good quality foam carpet padding directly over the veneer and then put a flat panel of MDF or whatever on top of it with the weight on that.The foam will distribute pressure evenly and take care of any irregularities.

    Pete
     
  12. Dan Wesnor

    Dan Wesnor Second Unit

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    You're going to need at least 5 PSI. That's a lot of weight for those boxes. Recommend you try clamps (lots of them), which can generate that much force. Use weight in the center if you can't get the clamps to reach. Use a piece of MDF over the veneer when you clamp. Test the method to make sure the glue doesn't come through the veneer. Let it dry overnight before trimming.

    I always use a utility knife to trim. Go slow and be patient. Glue is better for trimming than contact cement because it dries hard, where contract cement stays soft. Trim as close as you dare, and then use sandpaper to finish up. Pay attention to how the wood pulls the knife. If the grain moves the knife towards the box, turn around and go the other direction. Use both hands on the knife, one to steer and the other to apply forward motion. You get much better control that way.
     
  13. Pete Mazz

    Pete Mazz Supporting Actor

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    I've never used anywhere near that. 700 lbs/sq ft seems like a lot to me.

    Pete
     
  14. James W. Johnson

    James W. Johnson Screenwriter

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    I applied a test piece to the tops , the smallest area on each speaker. I only applied glue to the substrate and did not scrape nor let it set up much..I just pressed it down and pilled on roughly a 100lbs worth of stuff.

    The results were poor , also I do not like the trim look where you have to cut against the grain. I sanded off this veneer and I will try again.

    This time I purchased 8 bags of paver base (crushed rock) these are pretty compact bags and weight 80lbs each, I have 8 of them so 640lbs ..hopefully this will be enough.
    I will apply the glue to the veneer and substrate this time ...its paper backed so it should not bleed thru..I will also let it set up for abit before applying it and also scrape the surface really well with a snow scraper..I also bought a plastic paint scraper but while digging in my trunk today I found the snow scraper and I think it will allow more force.

    Lastly I will be trimming with a router this time, I just dont like the inconsistency and risk that cutting with a knife brings for someone in experienced like I am.
     
  15. Chris Keen

    Chris Keen Stunt Coordinator

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    I've had good success with a flush trim router bit. I would suggest that you use a good quality one, and try to only use this bit on veneers so that it stays sharp, and clean. Using it on contact cement applied veneers will tend to gum up a bit. I have never used a paint or ice scraper, but I tend to think that this might want to dig into or gouge the veneer. I have used a scrap of 2x4 or some other good peice or black of hard wood to use as a press, pressing along the piece to force any air out to the edges and sides to escape. If doing this with a glued surface, I would think that this might cause the surfaces to slip since the glue wouldn't be dry, therefor you might need to pin one end of it down with a clamp setup to keep it from sliding on you while moving your press away from the clamp.

    I haven't tried gluing yet, but I would like to try the method where you apply it to both the substrate and the veneer and let them both become dry, and then place the veneer ontop of the substrate and use and iron to activate the glue. This seems like a good method as long as you work from the center out to get out any bubbles. I think (for me) it'll be worth trying to see how my results compare to contact cement. Contact cement did turn out well by the way, just wanting to expirement.
     
  16. James W. Johnson

    James W. Johnson Screenwriter

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    Things are coming along nicely, I got the sides done and started the tops...in an hour or 2 I will trim the tops then get the backs started ..I should be able to finish in another day or two.

    [​IMG]
     
  17. James W. Johnson

    James W. Johnson Screenwriter

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    I just wanted to say thanks again for the advice, especially Pete..your information was very helpful and definately lent a hand in the success of my veneer job.
    Although there are a few minor errors in the veneer laydown and to the project over all , I am happy with the results so far. I just have a little more sanding to do before I start applying the poly.


    Pete, do you have some advice for me as far as laying down the Polyurathane? I bought a gallon of Minwax clear satin.

    As far as prep goes , how forgiving is polyurathane?
     
  18. Pete Mazz

    Pete Mazz Supporting Actor

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    Poly is not very forgiving and tough to touch up. Satin will hide minor imperfections in the veneer.

    My advice would be wipe it on. Thin the poly with ~10% naptha and use a lint free cloth to wipe on. Apply thin quick coats as it will dry pretty quick. Avoid trying to recoat before it has dried to the touch. If it's still a little tacky, wait. Sand lightly with 220 if the grain raises. Apply at least 3 or 4 coats. You can build up the finish as much as you want with subsequent coats.

    Pete
     
  19. James W. Johnson

    James W. Johnson Screenwriter

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    Pete, what do you mean by its tough to touch up? Do you mean if you scratch it or if you scratch it and the wood beneath it?

    I could not wait and I applied the first coat last night, the guy at Lowe's suggested I use a low nap mohair roller....boy was he wrong. After applying the first coat I hurried as fast as I could to try and undo the bubbly mess the roller made with a brush. I smoothed it out and scraped off as much excess poly as I could.
    It turned out better than I expected but still the coat was too thick.
    How can I fix this? Will over sanding the poly mess up anything for further coats?

    They sure look good from 2' and camera shots though. [​IMG]... but that wont do , I need close
    inspection good looks to some degree.
    [​IMG]
     
  20. Daniel Metcalf

    Daniel Metcalf Stunt Coordinator

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    Hey those are looking NICE. OH BTW I went ahead and got the Rythmik SE350, it's pretty close to the 40% of RMS figure and Brian goes through and changes some stuff to make it more "audiophile", all in all a pretty nice plate amp and it gets plenty loud enough. Maybe we should start an 1804 cult site?[​IMG]
     

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