You sound resourceful, but this is going to be a real challenge, and I'm not sure any of your proposed methods will work. Also, if you are thinking of getting a replacement panel, be aware that you'll never get one that will match the color or finish after all this time. I have taken down 1/4" paneling like this (mine was mahogany) without cracking anything, so that stuff may be tougher than you think. I would get myself a couple of flat prybars (they're often called Wonder Bars) and try to get one edge freed. When I'm prying, I use the bars in tandem: you get one of them slid in, and apply a little controlled force so you can open the seam up a little, then you put the next one in beside it, exert a little more force with the second one so you can remove the first one and insert it above the second one. You keep leaprogging your way up the seam until it's all free. If you can get one edge fully free, then you can prop it open, or have someone else hold it open while you get in behind it to the next firring strip. Work carefully, listen for sounds of cracking so you can stop and adjust before you break something, and pad the adjoining paneling edge that you'll probably be leveraging against so you don't damage it. As for the brads, the heads should pull cleanly through the back of the panel as you free it from the adhesive. Good luck, and let me know if you succeeded.

My experience with construction adhesive is that the bond is often stronger than the material it's attached to. In prying wood away from wood, the failure is usually in within the wood fibers and not the bond. Your best bet would seem to be trying to pry the furring strips off the concrete (you'd probably end up with a layer of wood fibers attached to the concrete) - you might be able to do this if you have baseboard and/or crown molding that you could remove to allow access. Just a thought. I'd be surprised if any solvent would weaken the adhesive after all this time. I've had trouble removing adhesive the next day!

ventupete-
I agree with you...it mirrors my own experience. I think the challenge here is getting an edge completely up so you can get your arm behind the panel and pry the rest of those firring strips off the concrete.

thanks all.

--probably thought I'd gone away, taking so long to answer.
It just seems one "challenge" follows another. The time goes by and you try to hold things together or repair things including your body and sometimes, things just keep coming.

Hopefully, I'm forgive for being long time in answering. It's been in & out of docs. for me and tonight, wife goes to hospital.

I managed to get a small, very small, strip piece of the paneling off, intact. I used a blow dryer to heat it. The adhesive cement is very, very strong. the blow dryer took a long time to heat the wood--I thought it was going to scorch , before the paneling came loose, but I finally got it. That 4"x4' section took over an hour of work!
There does seem to be though a magic temperature, if I can get up to it, the adhesive softens enough to let me hammer a putty knife between it and the wood, other wise--no go. the putty knife won't cut it and the piano wire I tried to use, broke.

I hoped that was the piece that would give me access to what I needed to work on, but no. I'll have to remove at least, maybe two, of the full 4x8 sheets.

If I destroy this Walnut, there will be no way to replace it. And I do not want to have to figure out some other way to refinish the basement--I guess I could glue sheet rock to the walls, if I glue enough shims in first. I just hope I can get the panels down. You'd think that 30+ year old glue after being so old and going through freezes and thaws would be brittle and give way, but it sure doesn't.

Probably the easiest way is to pry the furring strips from the walls and try to put them back up?

Because of the unevenness of the concrete walls the strips are glued on both horizontal and vertical. And to get them off, I'll have to take down the entire wall! -- ouch! Is that the only way?

I did such a great job putting this stuff up, I can't even see the finishing nails I used to make certain the panels stayed attached to the strips while the glue set. Then of course, I dabbed a bit of paint, the same color of the dark, vertical seams they are in, on the nail head. they are virtually invisible.

To find them, I hope a magnet will work. If I pull off the furring strips, they won't be a problem. If I try to take off the paneling, I'm not certain if I have enough room to drive them through the panels before they hit the concrete.

What a job. In removing the one little piece of paneling, I learned that I'm going to have to pull an entire corner of the ceiling tile down, as well. It just gets worse and worse...or maybe I should look at it as an exciting challenge? Let's see if I can do it? --yeah, right :(

Instead of using a hair-dryer to try to heat the wood, what about trying an electric iron? Think I could do that without scorching the paneling? If so, how high of heat would you set it to and what would be good to put between the bottom of the hot iron and the paneling? --I don't think laying an iron, directly on the walnut, would be very good for it.

Or should I just give up and try to separate the furring strips from the wall, leaving the paneling attached.

--What a nightmare it was putting those up--absolutely nothing was plumb, level. It took hours and hours to get them level and plumb. Maybe there's an expert way to get these down--it'll take at least 4 people to take a wall all in one piece, especially to not cause damage to any of the panels. Then, how do I get it back up?

Is it time to throw the walnut away and put up sheet rock?

Bob

Another way to cut through cionstruction mastic is with woven fishing line between some handles.
You use it like a saw to heat and cut the mastic.
for 4 foot wode panels you would neeed 2 people to alternately pull back and forth.
It is very slow and time consuming, but probably faster than just prying.

It may be time to consider putting drywall at least in part of the room.
The work goes a lot faster if you simply frame a 2x4 (or even 2x3) wall just off the existing foundation and then go from there. you loose a few inches of floor sapce, but gain some insulation room behind the finished surface.

that's a good idea, to frame and put in a new wall.
I would definitely loose floor space and there'd be a few problems, but nothing like pulling down, intact, the paneling.

I'd probably have to frame the whole room though, otherwise it'd look a little strange to have 3 walls paneled and one, sheet rock. But it would certainly help with insulation. The paneling has about 3/4 in of space behind it, but it's just cold air.

Then, though, I'd have to give up the warmth (color) of the light walnut--it's quite nice, but outdated.

Too, there's the question of what to do with the bare sheet rock? I guess, just paint it white and let it go?

It's hard though to tear down work that took months.

I wish I knew at what temp to set the iron if I'm going to try and soften the mastic without scorching the paneling.
You sure are right that will be a big job. I really thought my piano wire would cut through it. Maybe fishing line will do better. decisions, decisions.

Thank you all, for the help.

Bob T.
And what do I do with the sheet rock and new wall? cold air, but some sheets of

one other question (I guess I can make a new thread or do a search--but I'll ask)

If I do go for putting up a non-load bearing wall, suggestions as how to attack it to the floor?

The floor is 50+ year old solid, and I mean solid, cement.

I've tried driving cut nails into it, also drilling into it--broke the nails, ruined my bits.
Do I use construction adhesive again? --a bead on the floor and if I can, some spots on the vertical, where the cement wall comes near the lumber? --because of the waving of the walls, that may be only one or two points.

A few inches of foam insulation has a lot of insulation value.
The drawback is that the material costs more than fiberglass.

The fishing line trick works be generating heat as it is 'sawed' back and forth.
You could always try a heat gun and work slowly until you find the right time/temperature combination. Most have adjustments for airflow to change the temperature. Wide open lots of warmed air. ALmost fully closed a little very hot air (hot enough to melt lead).
One painted contrasting wall might not look that bad.
I would go for a white wall, or only slightly tinted.