mopar dave Posted March 7, 2004 Share Posted March 7, 2004 have'nt started the khorn build yet, july looks like the build date. once i get done with an engine build for the barracuda i can get started on the khorns. anyway, just wanted to get your opinion on some lumber i found at minards, another home improvement store. "fiber core plywood" with oak laminate. never seen this stuff before and wondered if i could use this instead of the baltic birch? $33 for a 4'x8' 3/4" sheet. not sure how the ends would be finished. dave Quote Link to comment Share on other sites More sharing options...
djk Posted March 8, 2004 Share Posted March 8, 2004 Considering how low priced Batlic Birch is right now, ~$21 per 5 X 5 sheet, it would be foolish not to use it. The other product you described is glorified particle board. Quote Link to comment Share on other sites More sharing options...
kktvbob Posted March 8, 2004 Share Posted March 8, 2004 When I ordered my Cornwall in 84 it was said that the birch was the best sounding of the woods PWK offered. I don't know if its true or was just bs so don't flame me on that. But that particle board can not sound as good as a hardwood ply. By the way what is the year and the motor is that mopar my 68 GTX 440 convertable go's back in the body shop Monday morning. Quote Link to comment Share on other sites More sharing options...
mopar dave Posted March 8, 2004 Author Share Posted March 8, 2004 thanks for the replies guys. i was just curious about that fiber core, never seen it before. tvbob, the car is a 67 barracuda notch back. the engine i'm building is a .030 over 360 block with 4.00" crank, makes for a 408 stroker. shop tells me will make 500 horse by accident, and mega torque. my idea is to make big block torque with a small block. whats your GTX going in for? dave Quote Link to comment Share on other sites More sharing options...
Malcolm Posted March 8, 2004 Share Posted March 8, 2004 You are going to have one hell of a car. The 1967 Barracude fastback I had with a stock 383 could smoke the tires all the way into fourth gear. So much torque for so little weight. Your notchback will be even more so when your motor build is done. FWIW MDF with a hardwood veneer can make a good looking, good performing speaker cabinet. What it cannot do is take much of an impact. Much better to use baltic birch and veneer with whatever you like if you are going to go to the trouble of building your own speakers. Veneered MDF can, however, be used to advantage in internal parts not subject to impact, Quote Link to comment Share on other sites More sharing options...
djk Posted March 9, 2004 Share Posted March 9, 2004 "Veneered MDF can, however, be used to advantage in internal parts not subject to impact" You got that backwards. I'd like to see you make a pair of Klipschorns using 1/2" MDF for the interior boards. Put all those fasteners in ON EDGE, into boards at an ANGLE. It would not survive being shipped. You might get away with making the front and the top out of 3/4" veneered MDF. You're going to spend 100 hours building and finishing these, you want to risk it? Quote Link to comment Share on other sites More sharing options...
mopar dave Posted March 9, 2004 Author Share Posted March 9, 2004 no, your right. i don't think i'll risk anything with the money and time we'll have into them. i'll stick with the original plan, baltic birch interior and a1 grade oak veneered 9 ply exterior(front and top). thanks Quote Link to comment Share on other sites More sharing options...
Malcolm Posted March 9, 2004 Share Posted March 9, 2004 If I've got it backwards, then MDF can be used for parts subject to impact! I think you have your head up your *ss! Quote Link to comment Share on other sites More sharing options...
kktvbob Posted March 10, 2004 Share Posted March 10, 2004 My GTX went inthe bodyshop for some touchup its a ground. Boy the time and money but it looks great. I'm going to keep this one mild around 450 to 475hp. My next one a 57 DeSoto Firesweep with a 392 hemi will be the big horsepower car but thats not till I get the GTX done. Somewere I also need to finish my home theater. Quote Link to comment Share on other sites More sharing options...
HDBRbuilder Posted March 10, 2004 Share Posted March 10, 2004 Malcolm, you misunderstood his point...for the parts of a K-horn build, with the exception of the upper housing parts and the bassbin front panel itself, to use ANY KIND OF FIBERBOARD or PARTICLEBOARD is pure FOLLY. The fasteners will just blow out along the edges of the parts if particle or fiber board is used there...not only that, but the glue won't hold worth a damn on those edges. That is what he menat...and that is why, even today, on the K-horn, veneered MDF is ONLY used for the parts I mentioned above...with baltic birch or 7-ply (with two veneers atop that)3/4" birch being used on the rest of the bass bin...pretty simple! There is still a small bit of solid wood needed for splitters, reinforcement blocks on wings, and such, though....one straight, knot-free, tight-grained fir 2x4 stud should suffice for those parts though. Quote Link to comment Share on other sites More sharing options...
John Warren Posted March 13, 2004 Share Posted March 13, 2004 ---------------- On 3/9/2004 4:17:24 PM Malcolm wrote: If I've got it backwards, then MDF can be used for parts subject to impact! I think you have your head up your *ss! ---------------- Sir- djk is one of a handful of members on this BBS that provides information of value. What he said makes perfect sense. jw Quote Link to comment Share on other sites More sharing options...
John Warren Posted March 13, 2004 Share Posted March 13, 2004 Here are the glue-joints of interest. From the last pair of Klipschonrs I built 5 years ago. After 30+ years, I've got 4 pairs under my belt. Note, btw, the bare edges are first glued, the glue allowed to dry, the edges then sanded and then the pilot holes are drilled using the mating board as a template. Note too, how the holes are located, baised to one side of the board (on the large panel that makes the "V"). Done so that the screw don't puncture thru the inside chamber. Assembly is not trivial. Quote Link to comment Share on other sites More sharing options...
formica Posted March 14, 2004 Share Posted March 14, 2004 Were the original Klipschorns built using 1/2 plywood for their construction? I have a set of plans (German) that lists a series of 1/2 and 3/4 (13mm and 19mm) pieces. It seems that any possible savings in material would have been lost in the more complex construction? Are the current versions all in 3/4... and are there any corrected plans for the thicker panels? Andy, I have your corrected LaScala plans, and Im sure you mentioned this in another post but I dont seem to have it written down... but dont recall seeing the panel thickness?. Is it 5/8 like the german plans... or are your values corrected for 3/4 Thanks... Rob Quote Link to comment Share on other sites More sharing options...
Q-Man Posted March 14, 2004 Share Posted March 14, 2004 Klipschorns were and are 1/2" for the horn folding. The face board and the top sections are 3/4". The LaScalas were and are constructed with 3/4". Quote Link to comment Share on other sites More sharing options...
fini Posted March 14, 2004 Share Posted March 14, 2004 I'll second (or third?) the advice not to use MDF here. I worked for a guy that loved to bring us window jamb extension material ("window wraps") made from MDF. It is nearly impossible to edge-nail or screw it together without the layers splitting apart, like cleaving slate. I was overjoyed when we got to use real wood! MDF certainly has its place. I've used 1-1/2" thick "ultralite" MDF for a bookcase, using biscuits to join, and it worked great. I've also seen MDF display cabinets in a store where they had used a clear finish. It actually looked kind of cool. Quote Link to comment Share on other sites More sharing options...
mopar dave Posted March 14, 2004 Author Share Posted March 14, 2004 i'll make sure to stick with real wood for the complete build, 1/2"baltic 13 ply, 3/4" 7 or 9 ply for front and horn cabinet. Quote Link to comment Share on other sites More sharing options...
HDBRbuilder Posted March 14, 2004 Share Posted March 14, 2004 Formica, 3/4" birch plywood is the material for LaScalas, but Klipsch used cabinet-grade 3/4" birch that had SEVEN instead of just FIVE core plys between the two outer birch veneers....it was specially made by Georgia-Pacific for them. The other day I was looking at a NEW pair of LaScalas at the local dealer here...they are STILL using that seven-core ply 3/4" birch plywood for them. The dimensions I put on those German plans were measured directly from a pair of 1977 Klipsch factory LaScala cabinets...and are right on the money!! If you use those dimensions, allow for a bit oversize on the side panels vertically AND horizontally, so that there will be some overlap at the bottom and rear that can be sanded flush with a belt sander, just like at the factory...an additional 1/32" will suffice. The sides, when assembled to the rest of the cabinet, are flushed at the front side and top edges of the upper H/F motorboard...and at the front edge of the bassbin bottom panel, which will leave a slight overhang at the rear and along the bottom...a belt sander solves this problem. Other than the motorboard, the front panel, and the materials used for glue blocks and spacers, all the panels used in a K-horn bass bin are 1/2" baltic birch...this replaced marine grade fir in the early 1970's. In the interior pic above of the K-horn bass bin...you see that a glue block of 1/2" plywood was used at the junction of the two panels that form the "dihedral" of the "wing" section....upper "wing section"(shown) and lower "wing" section (not shown)...at the factory they used solid yellow pine for this block, ripped from 2x4's....this eliminated the possibility of splitting in the plys from fasteners if using plywood there...which would necessitate rebuilding that wing section. Time is money! THat particular glue block was installed in those assemblies OVERLENGTH, then...after the glue set up, those wing pre-assemblies were taken to the bandsaw where those overlength glue blocks were carefully trimmed flush with the panel edges. YES...I remember how it ALL was done...I sure outta, I must have done it a million times! LOL! One IMPORTANT note here...there is NO SUCH THING as 1/2" baltic birch...since it is actually METRICALLY-sized...but it is CLOSE to 1/2"...maybe 1/32" off in thickness!! EVERYTHING that comnes from Russia is metrically-sized...although, often approximating our standard sizes here...Russia adopted the metric system between WWI and WWII...after the overthrow of the Czar...prior to that they were unique in using the arshin as their unit of measure...an arshin is closer to a meter than to a yard in length....but is NOT the same length as either of them! Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 14, 2004 Share Posted March 14, 2004 My son got some Baltic Birch for making his flexi rack, that has 13 layers, plus the two outer thin layers. That stuff is stiff! He went back to buy some more and they didn't have any. Marvel Quote Link to comment Share on other sites More sharing options...
HDBRbuilder Posted March 14, 2004 Share Posted March 14, 2004 Most any lumber supplier to local cabinet shops will have bundles on top of bundles of baltic birch in stock. In both the metric equivalent of 1/2" and 3/4"...even in thicker material!!....and the cover sheets for those bundles normally get thrown out...but they make GREAT drawer bottom material!!! They would ALSO be great for anybody wanting to replicate the old wooden laminated mid-range horn lenses like Klipsch used in the early K-horns!!! Hint, Hint! Cover sheet material runs almost 1/8" thick, and is three-ply....tough, but somewhat flexible...Good stuff to have around a wood shop! Quote Link to comment Share on other sites More sharing options...
formica Posted March 16, 2004 Share Posted March 16, 2004 Thanks for the details HDBR... I saved them with your plans. If I'm unable to eventually find a Klipschorn locally, I may consider building one from a parted out LaScala. Unfortunately I have to many ongoing projects right now to even consider such an involved build... so finding a set within a 6hr drive is still my best option. Thanks again... Rob Quote Link to comment Share on other sites More sharing options...
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