Looking for advice on veneering vintage speakers

[Justin Pfenning]

I have a pair of KLH Sixes that sound wonderful, but show their age and years of handling. I have purchased some walnut veneer and veneer glue from Veneer Supplies, and I'm going to give this a try. I've never veneered before, so I plan to do some test panels to get my process figured out. I plan to use caul boards to clamp the veneer, since the speakers won't fit in vacuum bags very well. I'm open to any and all advice or experience you would like to share. I really want these to turn out nice, so I can display them in my house with pride.

The attached pictures show the abuse the corners of the cabinets have taken over the years. My first task is to fix these corners, providing a solid base for the veneer to glue too. I considered fixing the corners with bondo, epoxy, or rock hard water putty, but I think I've settled on sanding the corners flat, and gluing on a piece of particle board (the cabinet sub-straight) or soft wood, then using my pull saw to saw it off close to flush, then sanding the repaired corner flush with the 3 sides. Bondo, epoxy, or water putty might work on the small corner dings, but I'm afraid that big corner chunk won't come out very well unless I use wood or particle board. Please share any insight or experience you might have with this type of repair. I have attached picture showing the corner damage.

As far as veneering sequence, I thought doing the sides first, then top, then inside the face (where the speaker grill goes) then the face of the speaker last. Does this make sense? My veneer is plain wood, no paper backing.

I'll probably finish the walnut with an oil of some sort, and top coat with wipe on poly, or shellac. I've had good results with a tinted Danish oil under WOP with a stereo rack I built. I plan to use my test veneer pieces to work out my finish plan. In the end, I hope to have a pair of speakers that look like the other 2 pictures attached. The last 2 pictures show the simple stereo stand I recently built.


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[roger wiegand]

If you'd like some to practice on I can send you mine! I bought those used when I was in college, and they produced great sound for many decades of daily use. I suspect the speakers need to be re-coned by now, but the corners on my enclosures look exactly like yours!

Yes, a "dutchman" will probably make the longes-lasting repair. Given that the enclosures are particle board though a slurry of sawdust and epoxy wouldn't be an inappropriate repair material either. Just use tape to make a form, pack it with a mostly sawdust mix, then sand it flat once it's hardened.

[Phil Mueller]

I’ll give you my somewhat novice 2 cents. If you are also redoing the back, I’d do back first, then the sides, then the front, then the top. Don’t go too crazy with the glue...an even thin coat is all it takes (I can still see wood grain through the glue). Only put glue on the cabinet, then apply the “dry” veneer to that. Leave an 1/8th” proud on all the edges. Be sure to put wax paper between the veneer and the cauls. Clamp for about an hour (or whatever the glue states as clamping time) and remove from the cauls. I like to clean the edge right after I remove it from the cauls while the glue squeeze out (if any) is still somewhat soft.

On some glue ups, when I put the veneer onto the glued substrate, I use thin masking tape to tape the veneer down in order to minimize (or eliminate) any veneer movement while getting it into the cauls. Most likely once the veneer hits the glue on the substrate, it will begin to curl some...so tape helps keep it aligned.

After it dries, check for any areas that may not have glued down tight (particularly around the edges). No big deal to push in a little glue in those areas and reclamp.

Keep in mind that even though commercial veneer is very thin, it does have an end grain that will show around the top edge (if you do it in the order I suggested above).

Hope that helps a little.

[Jamie Buxton]

I only use vacuum veneering now, but as you say that's not going to work with a hollow box. Back when I used to try veneering with mechanical pressing, it was veeery sketchy. Maybe it would work right, but mostly it didn't. There would be glue voids or the opposite -- glue humps where I'd sand through the veneer. Nowadays, you can buy veneer with a peel-and-stick adhesive on the back. I'd use that for your speakers. You can buy PSA veneer from tapeease.com, veneersupplies.com, and others.

[Richard Coers]

I only use vacuum veneering now, but as you say that's not going to work with a hollow box. Back when I used to try veneering with mechanical pressing, it was veeery sketchy. Maybe it would work right, but mostly it didn't. There would be glue voids or the opposite -- glue humps where I'd sand through the veneer. Nowadays, you can buy veneer with a peel-and-stick adhesive on the back. I'd use that for your speakers. You can buy PSA veneer from tapeease.com, veneersupplies.com, and others.
I helped a guy reface a kitchen with peel-and-stick and I thought it was crap. You have to used a hardboard type of squeegee to attempt to apply "mongo" force. That was right from the instruction sheet. I would only suggest using warm hide glue and hammer veneer the veneer on. I did one job for a church that wanted thin skins put on some slab doors. The edges of the doors were a mess. So I ran a rabbeting bit along the corners and glued in a 1/4"x1/4" strip inlay. Then flush trimmed that. It gave a wonder crisp edge to veneer to. Worked great!

[Justin Pfenning]

Roger, luckily the KLH Six has cloth surrounds, so no foam rot to deal with. The only need to be re-sealed with a special dope (along with the dust cap).

Thanks for the idea on the epoxy and sawdust mix. How wet or dry should the slurry be? I'm thinking I might go with the Dutchman fix on the bad corner, and try the epoxy and sawdust on the corners with less damage.

[Michael Drew]

I have done this to larger speakers that had cheap vinyl covering. I ran a ROS over the vinyl with 120 grit, then used contact cement to adhere the veneer. Worked great.

[Bruce Volden]

Justin,
I'm following this thread.
I have a pair of JBL Century 100's and a pair of L-166 JBL's as well!
They both need finishing as well as re-coning.
Now if I could find a decent amp?

Bruce

[Thomas McCurnin]

+1 on using a vacuum press.

I had KLH and Advent speakers as well I still own the Advents but they are relegated to our cabin. What was that guy’s name, the inventor. Klaus something. Smart guy.

[roger wiegand]

+1 on using a vacuum press.

I had KLH and Advent speakers as well I still own the Advents but they are relegated to our cabin. What was that guy’s name, the inventor. Klaus something. Smart guy.

Henry Kloss, Malcolm S. Low, and Josef Anton Hofmann are KLH. Kloss was a towering figure in the development of high fidelity audio, a founder of Acoustic Research, Advent, Cambridge Soundworks, and Tivoi Audio in addition to KLH. He invented the acoustic suspension speaker and built the first cassette tape player incorporating Dolby noise reduction.

[roger wiegand]

Thanks for the idea on the epoxy and sawdust mix. How wet or dry should the slurry be? I'm thinking I might go with the Dutchman fix on the bad corner, and try the epoxy and sawdust on the corners with less damage.

West says up to 50% sawdust. I've made it the consistency of thick chunky peanut butter to use as filler with no issues-- a paste thick enough that it doesn't flow. I'm not sure what the ratio actually was, I just added sawdust until the consistency seemed right.

[bill epstein]

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I don't envy you using un-backed veneer for your first time attempt. Or last time for that matter. I've veneered a lot of speakers over many years and the only success I ever had with un-backed was using PPR adhesive with cauls and enough clamps to start a railroad. My go to is NBL veneer from Tape-ease.com applied with contact glue, as used on the JBL based speaks in the pic.

All the rest of the advice here is spot on as to the repairs and order of facing.

Oh, and if you've got the 10 years it took me to learn to read a schematic without moving my lips, you can build some mono blocks as well.

[Justin Pfenning]

Justin,
I'm following this thread.
I have a pair of JBL Century 100's and a pair of L-166 JBL's as well!
They both need finishing as well as re-coning.
Now if I could find a decent amp?

Bruce

Bruce, hopefully I can pull this off to some reasonable extent. I'll post pictures as I go, but I don't work very fast. As for the amplifier I cannot tell you how much I love amps with EL84 power tubes. I'm sure your JBL's would love one too.

[Justin Pfenning]

430555
I don't envy you using un-backed veneer for your first time attempt. Or last time for that matter. I've veneered a lot of speakers over many years and the only success I ever had with un-backed was using PPR adhesive with cauls and enough clamps to start a railroad. My go to is NBL veneer from Tape-ease.com applied with contact glue, as used on the JBL based speaks in the pic.

All the rest of the advice here is spot on as to the repairs and order of facing.

Oh, and if you've got the 10 years it took me to learn to read a schematic without moving my lips, you can build some mono blocks as well.

Bill, I recognize those Pi4 speakers. I had a pair for a while running on my kit built 2A3 SET amps. Those are really amazing speakers.

What is PPR adhesive? I purchased the adhesive recommended by Veneer Supplies, but I don't remember the name at the moment. Looks like I need to add to my clamp collection again. I keep telling my wife it's impossible to have too many clamps. :D

[bill epstein]

Bill, I recognize those Pi4 speakers. I had a pair for a while running on my kit built 2A3 SET amps. Those are really amazing speakers.

What is PPR adhesive? I purchased the adhesive recommended by Veneer Supplies, but I don't remember the name at the moment. Looks like I need to add to my clamp collection again. I keep telling my wife it's impossible to have too many clamps. :D

Powdered Plastic Resin which is designed to be used with a mogambo heat press that gives instant bond. I get mine from Veneer Systems.
https://veneersystems.com/product-category/veneer-adhesives/ureas/

You measure out the powder by weight while holding your breath (of course now we all have N95s) and mix it with water. The adhesive will induce very little curls and spread properly will not clump or bubble. Then you use a veneer hammer or chunk of wood as with contact adhesive and mash the veneer into the resin like it owes you money. Now you can take a double layer of 3/4" MDF (have you given up yet?) the size of the workpiece and lay it on top. Clamp and caul every 6". Or invest in grape press screws and build a scaffold. 24 hours later you'll be rewarded with dead flatness and no bleed thru because of the solids in the resin.

After all that, the fellow that recommended it to me moved on to yellow glue and an iron (which I detest) and I joined the ranks of cabinet shop veterans who use paper or wood ply backed veneer and contact. It looks as though what you have is urea resin in liquid form and all the above applies.

The complexity of all the leafs of book-matched Fiddleback Anegre and Mahogany made the exercise more or less worthwhile on my version of the Altec Model 19 but I was younger and dumber than. Now I'm old and dumber.
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If I were you I would return the X-Press product and swap it for the iron-on one. Those KLH 6s are great classics but as a remodeler friend of mine is fond of saying, referring to re-framing a wall for instance, "we're not making pianos here, Bill".

[Paul Haus]

I've redone several speakers for customers over the years. Most I used a good contact cement and 2 ply veneer which worked OK. To put it down it was a J-roller along with a big, heavy rolling pin. To be honest the best pair I did, I used the old speaker enclosures as patterns and made new ones from hardwood. They looked great and sounded at least as good as the original cabinets did. I duplicated the cabinets as the originals were internally, used the front and baffling from the orignal along with the speakers and crossovers.
I'm not familiar with those speakers so it might be worth looking inside them and see how difficult it would be.

[roger wiegand]

I've had very good success using Tightbond and an iron for large surfaces-- sort of a variant on hammer veneering without the stress. There was an article on it in FWW decades ago. Use a roller to apply a thin coat of glue to the veneer and to the substrate. let it dry to the touch or overnight, than apply the veneer using a household iron. The PVA glue reactivates with heat, bonds tightly, and lasts forever. (well 40 years that I can personally document). I can also personally document that the commercial stick on stuff and contact adhesive don't last nearly that long.

[Dave Sabo]

I'm with Paul on this one.

Are you absolutely wed to keeping the old cabinet ? Even if you don't want solid wood , I'd think your veneer over mdf or baltic birch would be far superior to the low density particle board used by KLH.