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Alembic Club » Alembic Basses & Guitars » Archive through January 07, 2011 » Archive: 2009 » Archive through August 16, 2009 » Checking finish - delaying the inevitable? « Previous Next »

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garth4664
Junior
Username: garth4664

Post Number: 24
Registered: 10-2008
Posted on Sunday, August 09, 2009 - 8:16 am:   Edit Post

Hello Guys,

Thought I would ask the question - my 78 coco series 1 has been around the world a few times (I'm in hong kong now) and that has taken it's toll on the original finish which is still thick and glossy but is lifting where the finish is checking. If I oil the bass the checking almost disappears and it almost looks like new with the oil filling the gap between the checks and the wood underneath. This lasts about six hours until the oil is absorbed and the finish looks checked again.

I don't want to refinish the bass it has been looked after and is not really dinged up, but the original finish will end up on the inside of my case in little shingles if I leave it like it is.

My question is - is there anything that I can do that will help stick the original finish back to the wood. I am thinking some sort of lacqur that can be rubbed into the micro cracks of the finish, but sets hard and any residue can be polished off the outside of the bass once applied.

Any ideas? I was thinking some sort of CA (superglue) could be used very very carefully but I am concerned that this may be absorbed too much by the top wood and may look blotchy.
serialnumber12
Senior Member
Username: serialnumber12

Post Number: 509
Registered: 12-2004
Posted on Sunday, August 09, 2009 - 8:59 am:   Edit Post

Leave it beatup looking .......there's nothing like an alembic that's been pimped!!!
gtrguy
Advanced Member
Username: gtrguy

Post Number: 240
Registered: 9-2004
Posted on Tuesday, August 11, 2009 - 9:47 am:   Edit Post

I just think it's a natural process. My 76 still has the original finish and it looks near new, with no checking/crazing whatsoever, but it must have sat in it's case most of the time. I think the only perfect cure would be to have Alembic refinish the instrument.

A lot of finishes you might apply will contain solvents which might further eat away your original finish. Most would require prepping the bass on some way in order for them to even stick. Maybe there is a water based finish the might do the trick?

Maybe you could take a pass or two with super fine steel wool to remove the loose stuff and then leave it?

Good luck and let us know what you come up with.

Bye,
Dave
keith_h
Senior Member
Username: keith_h

Post Number: 1348
Registered: 2-2005
Posted on Tuesday, August 11, 2009 - 11:16 am:   Edit Post

Don't use steel wool. It leaves behind metal filings that will eventually find their way into the pickups and electronics. If you wish to buff it use nonmetallic sanding/buffing pads.

Keith
gtrguy
Advanced Member
Username: gtrguy

Post Number: 241
Registered: 9-2004
Posted on Tuesday, August 11, 2009 - 4:50 pm:   Edit Post

Good point. I assumed the electronics and stuff would be removed before any scuffing, and then it would be blown off with air, but some things, like the humcanceler, just don't come off.
garth4664
Junior
Username: garth4664

Post Number: 25
Registered: 10-2008
Posted on Tuesday, August 11, 2009 - 7:48 pm:   Edit Post

Hmmm good point on the solvents, perhaps some pure bee's wax is the way to go, if I could heat it up and get it to run under the checks...

Also, just wanted to add that the finish is actually not bad at all, but it is nicer when it is "freshly oiled" and the cocobolo can shine through without the slightly crazed bits on top.
crobbins
Senior Member
Username: crobbins

Post Number: 425
Registered: 6-2004
Posted on Tuesday, August 11, 2009 - 8:16 pm:   Edit Post

The checking just add character to your bass.
hydrargyrum
Senior Member
Username: hydrargyrum

Post Number: 650
Registered: 3-2004
Posted on Wednesday, August 12, 2009 - 11:21 am:   Edit Post

I have to think that anything that gets beneath your finish is going to be a bad thing, including beeswax. Wouldn't this end up looking foggy when it dried?
dfung60
Advanced Member
Username: dfung60

Post Number: 391
Registered: 5-2002
Posted on Wednesday, August 12, 2009 - 8:15 pm:   Edit Post

Hey, I think you're making the problem worse by oiling the finished areas! The way that you avoid finish checking is during manufacture where the surface of the wood that's getting sprayed needs to be immaculately clean and oil-free so the varnish can properly adhere to the surface. You also need to pick a finish that expands and contracts in temperature and humidity changes compatibly with your body wood.

The classic cause of finish checking is when a cold instrument is warmed up too quickly - the finish and wood expand at different rates snapping the finish coating.

In your case, when you have cracks and oil it, you're contaminating the surface and probably causing the finish to let go even more.

I don't think you can undo this, but don't make it worse by putting oil on the broken finish!

Normally, I think you want to use oil only on the bare unfinished wood on your instrument - for a varnished instrument, that would only be the fingerboard. For the finished parts, you want to use a wax or polish to keep up the surface. Oil won't do any good there.

David Fung
mica
Moderator
Username: mica

Post Number: 6307
Registered: 6-2000
Posted on Thursday, August 13, 2009 - 8:29 am:   Edit Post

I'm with David on the use of oil being restricted to the fingerboard, the only unfinished surface on the bass.

If there aren't many places where the finish is in danger of falling off in chunks, you can secure it by sealing with super glue (CA). This would be a preventative measure to protect the wood from damage should there be lapses in the finish. How will it look? The only way to find out is to do a small test and see for yourself if you are satisfied. There are also many water-clear optical epoxies available, but they don't dissolve in acetone like CA. If you use CA or epoxy, use a variety that has low viscosity (the thinner the better) for wicking under the existing cracks in the finish.

You should at some point have the bass refinished, though depending on the amount of oil that's now under the finish, it might have to be an oil finish.
garth4664
Junior
Username: garth4664

Post Number: 27
Registered: 10-2008
Posted on Saturday, August 15, 2009 - 3:42 am:   Edit Post

Cheers thanks Mica,

I don't think there is excessive oil under the finish as the cocobolo didn't seem to absorb it much (its very hard) and the cracks are quite small. will definately stop with the oil now that I know it could do much more harm than good. I think I will try the CA on some cracks on the back and see if this looks OK.

The bass would look amazing refinished but generally I don't like to take away from the originality of instruments (one of the reasons I am considering getting a new one built instead). The old 78's skin is a litte wrinkly but somehow she wouldn't be the same with a full refinish.

While we are on the subject - do you think you could email me a quote on the "dreamcatcher" in dreaming of for now section? An option for the point with alembic inlay (gustimate quote) would also be nice.

Thanks very much for answering my question to the club personally - much apppreciated.

Garth

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