cabinet refinishing

[Guest John Faulkner]

ANy suggestions on refinishing a pair of AR-2a cabinets. These are walnut (I believe) with a glossy lacquer (?) finish, pretty badly scratched up, also large chunks gouged out of the solid wood framing the grill cloths. Grill cloths themselves are really ugly multi color, although maybe original. I think I will cut new masonite panels for the grills and maybe replace cloths and make new velcro attachments. If I replace the existing damping material - old off white, quite dense, maybe rock wool, how much pink fiberglass per cabinet should I use. I see 3 1/2" mids available - anyone recommend replacing the dual 5's? The speakers have the old 1 3/8" phenolic domes, pots have been bypassed but I plan to clean them up and use them again - at present a little too much high frequencies for my ears. What caps are there in circa 1962 AR-2a? I would like to order new ones (with a little inductor bypass?) before I take woofer out to re-do pots. Thanks for any help

John

[genek]

ANy suggestions on refinishing a pair of AR-2a cabinets. These are walnut (I believe) with a glossy lacquer (?) finish, pretty badly scratched up, also large chunks gouged out of the solid wood framing the grill cloths.

It's hard to say what you should do without seeing what you have. Can you put up some pics?

[Guest John Faulkner]

Sides not bad tops a little scratched bottoms quite scratched and of course gouges in trim around front. Quite glossy finish - definitely NOT oiled. I woofer has been reconed, the other is original - seems to have a deeper "resonant frequency" when I lightly tap on the cone like a drum than the reconed one, maybe leading to different sound?

photos are top, bottom and side

bottom

gouge

side to show gloss

top

side

[genek]

Sides not bad tops a little scratched bottoms quite scratched and of course gouges in trim around front. Quite glossy finish - definitely NOT oiled.

AR walnut speakers were available in both lacquered and oil finishes. The front edge trim on my 2ax's is veneer, not solid wood, can't tell for sure from your pics what you have, but it looks like veneer to me. If it is, you can probably peel that strip off, build up the damaged area beneath it with wood filler and put on a new piece of edge band veneer. The rest of the cabinets don't seem to be too badly damaged, but are probably not candidates for a strip and refinish. I think you'll need to sand them at least a bit to smooth them out. If you don't have access to a spray gun and booth, I think your best bet for a new finish is probably stain and oil.

[JKent]

Hard to get a good match with edge band veneer. You might first try steaming the dents out--dampen it and use an iron and damp pressing cloth.

If johnieo chimes in here he may have some better suggestions--he does beautiful wood working.

Kent

[genek]

Hard to get a good match with edge band veneer. You might first try steaming the dents out--dampen it and use an iron and damp pressing cloth.

That's not a steamable dent. The veneer has been broken and sheared and the MDF below it has been crushed.

The veneer needs to be removed and the MDF rebuilt to shape with a filler. If (very big if) the strip of veneer could be removed without damaging it, then conceivably it could be reapplied and patched at the break, but the chances of removing it intact are small (funny how edge veneer always seems to come loose when you want it to stay and be impossible to remove when you want it to come off).

[zcon67]

That's not a steamable dent. The veneer has been broken and sheared and the MDF below it has been crushed.

The veneer needs to be removed and the MDF rebuilt to shape with a filler. If (very big if) the strip of veneer could be removed without damaging it, then conceivably it could be reapplied and patched at the break, but the chances of removing it intact are small (funny how edge veneer always seems to come loose when you want it to stay and be impossible to remove when you want it to come off).

If the banding was glued with contact, lacquer thinner will cut it. It will also cut the lacquer finish too if it is in fact lacquer. I use a turkey baster for large surfaces, maybe a dropper? Lacquer thinner is nasty and very flamable, take care if you use it. Deft is brushing laquer available at the box stores. It can be sprayed too. Carefull with that too.

PeteZ

[genek]

If the banding was glued with contact, lacquer thinner will cut it. It will also cut the lacquer finish too if it is in fact lacquer. I use a turkey baster for large surfaces, maybe a dropper? Lacquer thinner is nasty and very flamable, take care if you use it. Deft is brushing laquer available at the box stores. It can be sprayed too. Carefull with that too.

40+ years after it was originally put on I think the odds of finding out what the adhesive was are virtually nil. I think the best chance to remove it in one piece is probably to start with a sharp blade along the seam on the inside of the grill frame (AR usually didn't veneer that edge because the grill covered it, but just stained the MDF or plywood to match). If the veneer can be lifted a bit at the edge, then thinner could be tried (an eyedropper would definitely be better than a baster here, maybe even a hypodermic syringe if available). He could get really lucky and the glue could be brittle enough to let go with a bit of prying, but my experience says don't count on it.

The finish on the rest of the cabinet surfaces do not appear to be easily restorable and sanding and refinishing will most likely be required. The best procedure would be to attempt the repair first, if it fails replace, then sand the entire cabinet and apply an oil stain as needed to get the finishes matched. I wouldn't want to try spraying it unless I removed all the drivers first. Masking never seems to be 100% effective against spray leakthrough, at least not for me.

Another alternative would be to not repair the edge at all until after refinishing, then use burn-in sticks and graining pens to fill and regrain it after the rest of the cabinet has been finished. That approach does the least amount of messing with the original veneer, but is as much art and black magic as it is skill (I've been doing this sort of thing for 20 years, and looking at my most recent reffort I can still spot the repair even though my wife assures me that nobody else will be able to from more than 2 ft away).

[Guest John Faulkner]

Finally decided to attack these speakers. Replaced the re-coned woofer with and original cloth surround model, cleaned the pots and hooked them up again - they had been bypassed - I found it interesting that the yellow common wire went to the tweeter pot but not to the mid pot - they both had just green wire from cap to middle contact and then going from one outside lug to mids. Started by sanding the badly scratched bottom of one cabinet and found that they are more likely mahogany (maybe teak?) than walnut - if I know my woods. Lacquer sanded off pretty easily. So I thought what the heck and started to sand the framing wood - it IS solid wood, not veneer over MDF. The gouge on the edge was so deep that I decided to just bevel the edge all round at a roughly 45 degree angle - of course nothing like OEM but it gets rid of the edge dents nicely. Sanded both top and bottom, sides next, then I will most likely use an oil finish like Watco natural or maybe just a little color. Grills were pretty trashed - I think I will make new masonite grill frames and cover them with something other than the cloths they have now, even if they are original, they are a rather unattractive sort of tweedy brown - I have included pics of front and back which is darker but maybe more original if the fronts faded. I had thought of velcro mounting new grills/frames, maybe flush with front of cabinet but then I will get a lot of diffraction from the edges of the cutouts, or maybe make a deeper frame with bevelled cutouts a la my Thiels so no diffraction but grill cloth flush with front of cabinets. I was going to steal the tweeters for my AR-3s I am rebuilding but now I don't know - maybe will keep them in these and substitute 303a tweeters in the 3.5s as I call them as they will have 3a mids anyway and so will not be original. Still no answer on approximate year built SR 18346 and 18347, but I suspect 1962. Cabinets are plywood, not MDF.

front of grill cloth

Back of grill cloth

[Carlspeak]

Lots of loose, fuzzy fibers there on those grille cloths John. Grilles in that condition will most certainly attenuate the highs to a degree.

When you choose a replacement, go with something that has relatively smooth fibers with good open area (about 50% or more) and you won't sacrifice your high end that way.