Bacek Posted April 12, 2010 Share Posted April 12, 2010 I'm about to finish my first tracrtix 300Hz horn. As most of here I used bendable plywood for curved sides. I was my first contact with this material. It seems to be rather soft. So my concern is how to harden the surface to make it less absorbing for the sound wave. Any of you considered that? For a start I thought about hard floor varnish but I don't know if I'll be able to paint it black after. Quote Link to comment Share on other sites More sharing options...
Bacek Posted April 12, 2010 Author Share Posted April 12, 2010 Another PIC Quote Link to comment Share on other sites More sharing options...
sootshe Posted April 12, 2010 Share Posted April 12, 2010 For what it's worth, I got my ALK Tractrix horns in raw finish because I was going to stain them & leave them in a natural timber colour. For various reasons this didn't work out & I ended up painting them. I used 4 coats of grey undercoat, then 4 coats of satin black, followed by 2 coats of clear lacquer....they sound pretty good to me.[] Quote Link to comment Share on other sites More sharing options...
Pete H Posted April 12, 2010 Share Posted April 12, 2010 For what it's worth, I got my ALK Tractrix horns in raw finish because I was going to stain them & leave them in a natural timber colour. For various reasons this didn't work out & I ended up painting them. I used 4 coats of grey undercoat, then 4 coats of satin black, followed by 2 coats of clear lacquer....they sound pretty good to me.That's a good way to approach it. Nice work. Quote Link to comment Share on other sites More sharing options...
PrestonTom Posted April 12, 2010 Share Posted April 12, 2010 You are correct about being cautious if you are painting over a floor varnish (polyurethane). I have always had good luck using shellac to seal end grain and it can be painted also. Perhaps that would be a good candidate. One of the Zissner (BIN) products is a primer that has a shellac base (it is the one that has the label that recommends using alcohol to clean up - as opposed to water or paint thinner). You can find it at the larger Home Depots. Good Luck, -Tom Quote Link to comment Share on other sites More sharing options...
Bacek Posted April 13, 2010 Author Share Posted April 13, 2010 I used 4 coats of grey undercoat, then 4 coats of satin black, followed by 2 coats of clear lacquer Did you used wood dedicated undercoat/paints or a car dedicated? Quote Link to comment Share on other sites More sharing options...
DrWho Posted April 13, 2010 Share Posted April 13, 2010 So my concern is how to harden the surface to make it less absorbing for the sound wave. Any of you considered that? I don't think I'd worry about that too much. I'd just paint the horn however you think would look the nicest. Quote Link to comment Share on other sites More sharing options...
sootshe Posted April 13, 2010 Share Posted April 13, 2010 I used 4 coats of grey undercoat, then 4 coats of satin black, followed by 2 coats of clear lacquer Did you used wood dedicated undercoat/paints or a car dedicated? It was a multi purpose undercoat & top coat that could be used on a variety of materials....including timber & metal. Quote Link to comment Share on other sites More sharing options...
Bacek Posted April 14, 2010 Author Share Posted April 14, 2010 I don't think I'd worry about that too much. I was wondering if the problem with diy tractrix for higher frequencies/two way configuration was caused by too soft/absorbing surface? Quote Link to comment Share on other sites More sharing options...
Rick J B Posted October 5, 2014 Share Posted October 5, 2014 Are there plans for this horn? 1 Quote Link to comment Share on other sites More sharing options...
tigerwoodKhorns Posted October 5, 2014 Share Posted October 5, 2014 Are there plans for this horn? http://www.volvotreter.de/ 2 Quote Link to comment Share on other sites More sharing options...
Arash Posted October 5, 2014 Share Posted October 5, 2014 (edited) open the attachment in MS Excel. the calculation is set to a horn similar to V-Trac FC260, it's the last calculation I did. copy each column numerical data in Autocad command line and press Enter then you can see the shape. you can export it to Coreldraw or whatever you need for a paper print or a laser router or a CNC. hope this helps. Tractrix_v1.4b.zip Edit: attachment file is the same as mentioned in previous post. Edited October 5, 2014 by Arash 1 Quote Link to comment Share on other sites More sharing options...
Schu Posted October 5, 2014 Share Posted October 5, 2014 (edited) I would think some level of absorption would be a good thing... specially if you could not get a horn to resonant at 440hz. Edited October 5, 2014 by Schu Quote Link to comment Share on other sites More sharing options...
seti Posted October 7, 2014 Share Posted October 7, 2014 So my concern is how to harden the surface to make it less absorbing for the sound wave. Any of you considered that? I don't think I'd worry about that too much. I'd just paint the horn however you think would look the nicest. Agreed.. Just paint and clear coat it. Looks great so far. Quote Link to comment Share on other sites More sharing options...
djk Posted October 7, 2014 Share Posted October 7, 2014 (edited) . Edited October 7, 2014 by djk Quote Link to comment Share on other sites More sharing options...
minermark Posted October 7, 2014 Share Posted October 7, 2014 Bendable Ply eh ? Post link please. Quote Link to comment Share on other sites More sharing options...
longdrive03 Posted October 7, 2014 Share Posted October 7, 2014 Bacek, what brand of bendable ply did you use? It appears to be 1/2" with several plys. I've used 3/8" ply on some wooden horns but it only has 3 plys. Do you have the brand name? Thanks. Quote Link to comment Share on other sites More sharing options...
Ceptorman Posted October 7, 2014 Share Posted October 7, 2014 You guys realize this thread is 4.5 years old? He might not answer 1 Quote Link to comment Share on other sites More sharing options...
seti Posted October 7, 2014 Share Posted October 7, 2014 You guys realize this thread is 4.5 years old? He might not answer No.... Dang bumps..... I need to keep a look out for those. 1 Quote Link to comment Share on other sites More sharing options...
Rick J B Posted October 7, 2014 Share Posted October 7, 2014 You guys realize this thread is 4.5 years old? He might not answer No.... Dang bumps..... I need to keep a look out for those. Sorry, mang. Quote Link to comment Share on other sites More sharing options...
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