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New veneer on a pair of active ACTs

Sean K

Sean K

pfm Member
This may be well beyond my abilities, but I thought I'd ask.

I have a pair of SCM50s in black ash, a finish I dislike.

I am not bad at basic carpentry, e.g., have just refitted new skirting and architrave, managed to make accurate 45 mitre cuts, can manage mortise and tenon joints. I have a decent set of hand tools. I also know one end of a soldering iron from the other and in a past life, was very happy to put new speakers in bass (guitar) cabs, resolder a dry joint. As a kid, I was happiest playing with meccano or making scale models, was good at tech drawing, etc.

However, I have never worked with veneer of any kind. I would be happy to go with almost anything that had a 'natural wood' finish, e.g., cherry, oak - whatever would be easiest/most forgiving to work with. I'd obvioulsy have a practise run on a mock up box of some sort.

Briefly:

1) Could new veneer be laid on top of the existing one? It's in perfect condition - no dents, all securely bonded, etc. If so, what kind of preparation would be needed for the existing surface?

2) The front baffles on which the drivers are mounted would need to be taken off. These are attached with allen/hex bolts (not sure if these are tightened to a specific torque), as would the rear panel/ heatsink/amplifier assembly. What is the chance of disassembly (or more pertinently, reassembly) turning into a major undertaking? E.g., would there be any mastic/sealant nastiness to deal with?

I live about 18,000 km from the ATC factory, so if I did bugger anything....

These are well out of warranty, btw. Barring a lottery win, I can't see myself upgrading them/ moving them on, but obviously wouldn't want to devalue them.

Sean
 
The current veneer is likely to be plastic, if it is, that will be the problem, if it is contoured/textured things will be worse.. Even if you get a wood veneer to stick short term, unless you completely remove all the plastic first, I suspect it will be temporary.

Quite probably easier to make new cabinets.
 
The biggest problem in my eyes is the removal of the old finish to glue the new veneer onto. With the sanding likely to leave the surface uneven, the likelihood for blisters and bubbles after the glue has dried would be very high. If you dislike it that much, try sanding them back and restaining them. Far easier, with a little care and attention to detail, you can achieve some very pleasing results.
 
Sand your old veneer to remove any oil or varnish finish it might have. When sanding use a flat piece of wood lengthways, say 4" by 2" to back your sandpaper, and be careful not to round over corners - you want to preserve the flatness of the faces.

Next you need a sheet of mdf or birch ply a little bigger than the largest side you need to veneer. Two sheets is even better - less flexure. A matching sheet for underneath is good too, then you don't have to worry about clamps marking the underneath side. At least 4 sash cramps, more is good.

Get paper backed veneer. Cut with about a centimetre overlap all round. It looks particularly professional if you can get the grain to continue unbroken all the way round, round the corners and on to the next face - bear this in mind cutting if you want to achieve this.

Brush glue on the face and on the paper backing, then assemble and clamp up. A dry run before taking the plunge is a good idea - bear in mind things might slip around due to the glue when you do the real thing. Clean glue squeeze out with a damp blush and clean water until all gone.

Trim 1cm overlaps when dry with some sort of bearing guided router - a laminate trimmer, or even a smallish proper router.

Do the same for another side. And trim. Etc.

When you sand the veneer be very careful not to sand through, particularly at edges. Use the same block used earlier. Wet sanding has its adherents. Or you might try the french polishers trick of damping to raise the grain, allowing to dry, then sanding flat again. 7 times and it doesn't raise any more. You can use finer grits each time, end up with 400ish.

Then finish with whatever your poison is.
 
ff1d1l said:
..............................underneath side. At least 4 sash cramps, more is good.
………….…………………………....
Click to expand...

I think that you mean G-cramps (or equivalent).

A safer way to finish is to use wire wool or flour paper as a light abrasive, apply one coat of sanding seal (which raises the grain), wire wool or flour paper again, and then finish with wax/polish as desired (use a random orbital sander and bonnet).
If really not interested in polish, skip the sealer, go to a varnish of choice, perhaps with a diluted first coat, and flat between coats with wire wool or flour paper.
 
Vinny said:
I think that you mean G-cramps (or equivalent).

A safer way to finish is to use wire wool or flour paper as a light abrasive, apply one coat of sanding seal (which raises the grain), wire wool or flour paper again, and then finish with wax/polish as desired (use a random orbital sander and bonnet).
If really not interested in polish, skip the sealer, go to a varnish of choice, perhaps with a diluted first coat, and flat between coats with wire wool or flour paper.
Click to expand...
No, I mean sash cramps.

717 x 304 x 425mm
 
One hell of a lot easier with G-cramps, and mahoosively cheaper, unless you already own or can beg, borrow or steal sash cramps...……………………………………

Just clamp through the thickness of each face, rather than face-to-face (side-to-side), with packing etc.

4 x 2 sanding block is also not really big enough to easily avoid sanding through, far better to use something that will take half or an entire sheet of abrasive paper. For sure, DO NOT use any kind of power sander - leave that sort of thing to professionals who know what they are doing from long experience.
 
Since even quite old ATC's are likely to be worth north of a few grand it might be worth checking out what a local cabinet maker or furniture restorer could do with them.

I don't think I'd like to make a thing like that my first attempt at veneering!

If done well it will probably add value.

Fox did something like you're suggesting a few years back but he doesn't post here anymore.
 
Thanks very much for the helpful advice and pointers.

I do fancy having a go myself (and have a set a 4 sash cramps - they get used about once every 10 years).

What I'm taking from this is that I don't need to remove the old veneer (peel/strip the sheets) from the carcasses as long as I can (very carefully, with a large, perfectly plane surface) sand through the finish on the existing veneer?

I know that patience pays off with these sort of tasks. I picked up a Japanese Fender Jazz 20 odd years ago that someone had done an awful sanding and staining job on. Thankfully, the stain hadn't gone very deep, but I remember well how each stage of sanding (progressively finer wire wool) and bringing the grain back up eventually gave it a lovely, glass like finish with several coats of oil and finishing off with decent wax.

I'll ask ATC for advice about disassembly; it's really only mastic/sealant and any specific torque settings I'm worried about (but who knows what I haven't anticipated?) If I can manage that, I'll practise with a mock up box and perhaps call in the professionals if/when my attempt looks like a failed CSE woodwork project.

Cheers

Sean
 
Vinny said:
One hell of a lot easier with G-cramps, and mahoosively cheaper, unless you already own or can beg, borrow or steal sash cramps...……………………………………

Just clamp through the thickness of each face, rather than face-to-face (side-to-side), with packing etc.

4 x 2 sanding block is also not really big enough to easily avoid sanding through, far better to use something that will take half or an entire sheet of abrasive paper. For sure, DO NOT use any kind of power sander - leave that sort of thing to professionals who know what they are doing from long experience.
Click to expand...
Last ones I did were 908 x 552 x 400, successfully.
You don't always get good access through the driver holes 15" bass yes tweeter no - in fact as I have quite a few sash cramps, I didn't even consider it. Another advantage of pressing down the veneer with a sheet like that with sash cramps is the edges tend to be just slightly favoured, and that is the area you really want bomb proof. No reason why you couldn't whack a few G clamps on too, though, belt and braces.
4 x 2 is fine, and very controllable. But I did cheat and make up several blocks with industrial sander belt glued on. Bigger would work too, but that worked fine for me. Never tried iron-on veneer as Pete suggested, but I guess that could fly too.
There's video on youtube of veneering with hide glue - I work with hide glue all the time and wouldn't dare do it!
 
I'd not use wood glue or iron on for this project. Unless you can sand all the finish of the black ash easily, you'll find they don't stick that well. You want to use contact adhesive for this job. It looks pretty scary, but it's pretty quick, and permanent. You don't need loads of clamps either, just a decent roller and a few sticks.
 
If you are using contact adhesive cut some cardboard strips, lay the on the cured glue then place the veneer on top and cairefully remove one at a time.
This way you can get it aligned before it sticks.

Pete
 
Sean K said:
2) The front baffles on which the drivers are mounted would need to be taken off. These are attached with allen/hex bolts (not sure if these are tightened to a specific torque), as would the rear panel/ heatsink/amplifier assembly. What is the chance of disassembly (or more pertinently, reassembly) turning into a major undertaking? E.g., would there be any mastic/sealant nastiness to deal with?
Click to expand...

The bolts for the baffles and the drivers are done up "just tight enough" .. there is no torque setting as the fittings are biting into wood/mdf so are not really torquable.

As the cabinets are 'ported' the use of mastic is pointless...it doesn't matter how 'leaky' the baffles are because there is a chuffin big hole in the front of it.

If the finish on the baffles themselves is okay then you don't need to remove the drivers from the baffles. You can just remove the baffles with the drivers in situ and just remove the cables from the drivers.
 
Sean K said:
2) The front baffles on which the drivers are mounted would need to be taken off. These are attached with allen/hex bolts (not sure if these are tightened to a specific torque), as would the rear panel/ heatsink/amplifier assembly. What is the chance of disassembly (or more pertinently, reassembly) turning into a major undertaking? E.g., would there be any mastic/sealant nastiness to deal with?
Click to expand...
There's a list of torque settings here which may be useful, including the baffle bolts. But I would always confirm the value with ATC. I do know of someone with a cracked baffle from over-tightening the bolts.
 
Thanks again everyone, including for the link to the torque settings and advice re pitfalls of various methods of glueing veneer.

Looking at various YT vids on applying veneer.

I'm due to get the music room done either next month or early next year (rewired, insulated and relined), so that will be a good opportunity to have a go at this.

I'll see how a trial on some mock boxes goes and depending on how I feel, will have a go myself or seek out a local cabinet maker or antique restorer.
 
Hi,
Someone on another thread said use wood glue as it allows you to position the veneer, then use panels to put pressure on the veneer for the glue to dry.

I previously used the contact adhesive, and then a wallpaper join roller to smooth out any bubbles. I varnished the end result with no issues. Sequence of veneering was sides, top and then front, trimming the edges with a scalpel. Bottom and rear panels were painted black.

Veneering is my preferred option as paint (spraying etc) does not offer good results unless you use a professional service.

Regards,
Shadders.
 
Advice on how to veneer and what to use will depend on just how good a finish you want to achieve and how handy you are at this sort of thing

If going for a high quality finish I use raw veneer and wood glue, clamped. Only leaving a mm or 2 round the edges of the box to trim off. The more left on the worse the grain pattern matching gets. Also raw veneer can be flipped unlike paper backed and better for doing symmetrical cabs.

It’s more difficult to work with though and breaks much more easily than paper backed when trimming off or just cutting to size. So if attempting it definitely practise on a sacrificial box first!

If you’re clamping with sheets of ply or similar, be wary of using too much glue, and leaving it clamped for too long, it can go through the veneer and end up with a difficult piece of ply to remove, or will pull off some of the face of the veneer, even just after a couple of hours

Paper backed will be easier to work with and probably better unless you’re going for a perfect finish. Some people like to use yellow glue over white, and go for the technique of applying to both sides, leaving dry and re activating glue with an iron. I’m not a fan and prefer clamps, is a better finish for me

When sanding the old cabinet try and get a final sand at least with as big a block as you can make, out of something nice and flat, it’ll help get a better finish and be easier to avoid rounding the corners over, if you do that it’ll be hard to put right and get the seams to look neat
 
You may wish to consider a recone of your drivers while you have them stripped, new caps in the crossovers. The original tweeters were only about £60 (8 years ago)
Look on the internet there is a video of re vaneer with zebrawood. ATC are very helpful they may even post empty boxes to you for safe posting. I think a new set of drivers was £1200 (8 years ago).
 
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