Refinishing Cornwalls

[Killer Fox]

I just picked up some new to me Cornwalls the other day. They are CBR that the owner finished many years ago. They are very faded on the tops and need completely refinished. Any tips you guys can give me would be great. I know birch is birch and I can Google general wood finishing techniques but I would rather hear from people here that own and have refinished these speakers.

Should I just sand or use a stripper first? Tape off / cover the speaker ports to keep dust out from sanding?

Should I use a pre conditioner before staining? Toner after? Top coat?

What brand/type of stain is best to use on these?

What color would you do? (I know, personal preference but I value opinions here). I want them to look classic as well as classy.

I do have new grille cloth on the way from Bob Crites.

Thanks!!

 

[Killer Fox]

Also can I use my electric sander or by hand only?

 

[macyjrm]

I have a pair of LaScalas in raw birch that are simply beautiful as they came unfinished from the factory. If your Cornwalls were mine I would simply remove the finish put on by previous owner and call it good. Once down to the bare wood you can apply oil (not stain) made specifically for maintaining butcher block cutting boards etc. to help protect the surface and make the wood grain "pop". Then re-oil every few months.

Certainly you can use an electric sander to take off most of the old finish since you'll have a lot of surface area to cover. If the old finish was applied thickly, a chemical stripper would be step one followed by light sanding. If using a rotary sander, just make sure to apply only light pressure to prevent burn through on the plywood layers. A small finish sander would probably a better choice but either can work again using low pressure. You have a really nice project going. We look forward to some before/after pics. Congrats on the Cornies. They are special.

 

[macyjrm]

One other point I left out above. Restoring these to their original condition will enhance their value for most Klipsch lovers in case you ever want to sell or trade them. The more you customize them results in fewer people wanting them.

 

[Killer Fox]

Thanks for the tips!! I thought about just doing the oil thing but I was afraid they might not look "finished". WAF is in full effect. That would make my life easier for sure!

 

[Output Relay]

If you sand, electric or by hand, always go with the grain. And remember, its veneer not a chunk of wood. Go easy. At that age using a liquid stripper might loosen the veneer from the base. And yes, mask off or stuff the horns. That fine dust won't be good for them. Just a thought

 

[usedto]

And remember, its veneer not a chunk of wood.

I believe the CBRs are Birch plywood, no veneer.

 

[Output Relay]

Don't mean to start any dispute, but even if it's a seven or nine ply Birch plywood the finish layer is still a veneer. Sand to deep and you get into the base ply which most likely wont be Birch. Even if it is, being plywood, the grain will be running ninety degrees the other way. That's the nature of plywood. Either way you'll only have about seven to nine sixty fourths of an inch to work with. A piece of eighty grit paper on a orbital sander will make short work of that material. I wouldn't use anything courser than a one ten grit paper just to be safe. This is all said about a sight unseen project, you never know for sure till you get started. Again, just trying to help.

 

[onepixel]

If they are just faded not scratched, I would sand them with a padded sanding block. The sand paper grit will be determined by the condition. Then use Howard's Restor-A-Finish. That alone without sanding will do wonders. The stuff is like magic.

I use Minwax stains. I completely refinished these Thiel 04a speakers. The cabinets were in sad shape. I used an orbital sander to start and hand finished.

Good luck!

 

[Output Relay]

Just more information to help you along. Klipsch's specks say the speakers are offered with a Black Ash, Cherry, or Walnut wood veneer finish with an MDF core.

 

[usedto]

From Klipsch:

4. Material for raw birch is/was Georgia-Pacific cabinet/furniture grade 7 ply (5 inner standard grade plies and the two outer very-fine grade plies).

My Cornwalls are CDBR - the decorator model. No grills, no finish - just good old Birch plywood. Of course, yours may be different.

 

[Killer Fox]

From Klipsch:

4. Material for raw birch is/was Georgia-Pacific cabinet/furniture grade 7 ply (5 inner standard grade plies and the two outer very-fine grade plies).

My Cornwalls are CDBR - the decorator model. No grills, no finish - just good old Birch plywood. Of course, yours may be different.

Did you finish yours or are the still raw?

I was reading about birch being stubborn and difficult to stain. I'm going to try just oil but not sure which one to try.

 

[usedto]

The original owner put some sort of stain on them. I haven't touched them since I got them.

 

[longdrive03]

I agree that you can use orbital sander on slow speed probably with 150 grit to take off the finish and smooth out the veneer. It's always good to go slow because it's hard to put the hair back on after you cut it. One thing you can consider is using wipe on poly made by Minwax. I use it in satin finish and it gives a hard finish. After about six or seven coats then send it with wet 400 grit paper dipped in water and dish washing soap till the shiny uneven areas are off. Then wipe it down with clean FYI cloth and then I use 0000 steel wool and Minwax finishing wax to smooth out the scratches left by the sandpaper and give a good smooth pretty finish. I wipe off the wax as soon as I finish one part of the speaker. You can buff it to bring up more shine. It gives a very smooth finish. You can find videos on line using this technique. Good luck and post pics.

 

[longdrive03]

I agree that you can use orbital sander on slow speed probably with 150 grit to take off the finish and smooth out the veneer. It's always good to go slow because it's hard to put the hair back on after you cut it. One thing you can consider is using wipe on poly made by Minwax. I use it in satin finish and it gives a hard finish. After about six or seven coats then send it with wet 400 grit paper dipped in water and dish washing soap till the shiny uneven areas are off. Then wipe it down with clean FYI cloth and then I use 0000 steel wool and Minwax finishing wax to smooth out the scratches left by the sandpaper and give a good smooth pretty finish. I wipe off the wax as soon as I finish one part of the speaker. You can buff it to bring up more shine. It gives a very smooth finish. You can find videos on line using this technique. Good luck and post pics.

 

[longdrive03]

I'm using Poly on Baltic birch ply now and it is very light and goes well in dark rooms

 

[longdrive03]

Here is pic.

 

[twiiii]

If you are thru all those steps to make your speakers perfect on the out side . How about some suggestions for the inside. front to back stiffeners and side to side stiffeners that interlock . Its not like composite or metal enclosures but every resonance reduction is a step forward. You might consider Bob Crites' new tweeters that should make you young folks happy who can hear from DC to light HZ.

 

[Output Relay]

Some Birch does not respond constantly with some heavy stains, and can be very problematic to stain if you are trying for a completely different color. The above stated hand rubbed oils would give you the best over all constant color and shading.