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Cracked wood...any hope?

Posted: 8 Jun 2006 5:08 pm
by J Hill

Hi,

I have a very old Gibson lap steel that had a slim but long crack in the wood when I got it a few months ago and its gotten worse and is wider now than it was. I didn't think that would happen since the wood should be stable by now but.... Is there any hope of making it look nice again? It it just a matter of filling in the crack or can the wood be pushed back together? The initial slim crack looked like it'd been filled a little. Can a good "restorer" do the job? Thanks for any info anybody can give me.


Posted: 8 Jun 2006 5:40 pm
by Ryan Spearman
A good luthier will probably fill the crack with glue and file/stain it to match the wood. It shouldn't be a big problem for you.

Also, I'm up in gilpin county...do you play with any local bands?

Posted: 8 Jun 2006 6:18 pm
by J Hill
Ryan,

Thanks for giving me hope. Did you ask if I play in a band? Give me just a minute here to catch my breath from laughing so hard.... I'm relatively new at this but enjoying it immensely. I'm sure I'll never be in a band. I do pedal mostly but am anxious to learn some lap stuff too.

Say, why are you not a member of our club here in Colorado? We sure have a lot of fun. If you're interested, write to me and I'll give you the info you need.

So are you in a band? Image

Thanks again for the encouragement.


Posted: 8 Jun 2006 6:58 pm
by Donald Ruetenik
I agree with Ryan. But take it to more than one luthier and interview them as to how they would remedy the problem.

Having not seen the instrument and going on your description, it may need to be laterally pinned or screwed together along with epoxy gluing after the previous 'filling' has been cleaned or routed out. Strategic positioning of the clamping and table jigging may need to be utilized to keep the instrument from warping or distorting. The factor of the crack worsening within a couple of months indicates another problem I couldn't address here. Is the previous 'fill-in' really a gluing that pulled apart?

Consider:
How does the instrument sound with the crack?
Does it stay in tune?
Is the crack merely a cosmetic annoyance?
Suppose the 'fix' would affect the sound adversely.

These are just some concepts that should be explored.

For years I played a beautiful sounding and playing acoustic guitar with a crack in it that I wouldn't dare fix and neither did the lucky guy who talked me into selling it to him. My only consolation (beside the handsome exchange) is that he dearly loves the instrument as does his girlfriend who cloisteringly appropriated it.

Posted: 8 Jun 2006 10:39 pm
by Dave Boothroyd
Don't do this with a good guitar, but the reason wood cracks is because it shrinks as it loses moisture.
Now there is one substance which will take the place of water in the Xylem matrix that holds the wood fibres together- and that is Ethylene Glycol- the main component in Brake Fluid.
If you allow glycol to soak into the wood, even large cracks will close. Glycol does not evaporate anything like as qickly as water, so the crack will stay closed, especially if it's glued as well.
There are not many cases where you can use this, but it's still a useful technique occasionally.
I discovered this watching a programme about the restoration of the Mary Rose, Henry V111's battleship.
I was able to make a steel out of a board of wood which was perfect for the job, but had been discarded because of a long crack.
The crack has not come back despite the fact the the guitar is kept and played in Africa.
Cheers
Dave

Posted: 9 Jun 2006 4:46 am
by Mark Vinbury
Will epoxy or regular wood glue adhere to glycol soaked wood?

Posted: 9 Jun 2006 5:56 am
by Bill Hatcher
Can you post a pic of the crack or email me one??

Posted: 9 Jun 2006 6:06 am
by Craig Stenseth
I think I'd rather "risk" using wood glue, than something this toxic.
Disclaimer: I am not a luthier.
http://en.wikipedia.org/wiki/Ethylene_glycol

Posted: 10 Jun 2006 12:12 am
by Dave Boothroyd
I did take pictures before and after working on the crack. I'll look for them on the hard drive and email them to you.
I applied marine laminating epoxy- which is very runny- (it's the stuff you use for glass fibre laminating), when the surface of the wood looked dry. It penetrates wood very well. I clearly did stick.
I do know that glycol is toxic- but I have no trouble resisting the tempation to drink brake fluid. Normal safety procedures are perfectly adequate- good ventilation, plastic gloves, no naked flames etc.
Cheers
Dave
Cheers
Dave

Posted: 10 Jun 2006 6:37 am
by Mike D
Post a pic when you can. The typical fix for a crack is to make sure the instrument is properly hydrated (sometimes that will close it on it's own but that depends on whether the crack is from dehydration or stress) and then the crack glued and clamped.
The sooner the better as cracks get all sort of gunk in them (left that one wide open for ya Howard! Image ) and that makes it harder tfor the glue to adhere)
I'd stay away from the glycol personally.
[edit]

D'oh! sorry, I see that you've fixed it already!

----------------
Half-assed bottleneck and lap slide player. Full-assed Builder of resonator instruments.


<font size="1" color="#8e236b"><p align="center">[This message was edited by Mike D on 10 June 2006 at 07:39 AM.]</p></FONT>

Posted: 10 Jun 2006 8:43 pm
by J Hill
Well, this is mostly a beauty flaw.... cosmetic, and my Cover-Girl isn't doing the trick. It sounds great and I didn't even consider that fixing it might hurt the tone. I could just leave it as is. But....

What's so puzzling is this guitar could not have had any moisture whatsoever in it after 60 years or so, unless somebody had it in a humid climate for a few years. I mean this tree has been out of the ground for a looong time. I have an old ('57) Gibson ES 130T thats blond and beautiful and its in perfect shape and it never gets humidified.

Anyway, thanks to everybody for the good education. I think I'll take it in for a check-up. I just hate these beauty flaws. haha


Posted: 10 Jun 2006 11:25 pm
by Chuck Fisher
sometimes luthiers will shave a piece of similar wood, put tightbond on it, then work it into crack, then , shave and sand to match after drying. I saw this done to a spruce top, almost invisibly.

Posted: 11 Jun 2006 12:43 am
by Doug Beaumier
I had a pre-war Gibson EH-185 (sunburst finish) with a crack in the wood, and my local guitar shop said that it would be best to just leave it as is. Repairing the crack is the easy part... matching the old finish is very diffucult, and the refinished spot would probably look worse than the crack.

Posted: 11 Jun 2006 10:05 am
by Bill Hatcher
I was hoping for some pics but since there are none, I would recommend just taking some 1/2 sec. CA glue and a long tube applicator and very carefully just start to inject the glue in the crack once a day until it filled all the area inside and to the surface. You can lightly sand CA glue starting with 600 and finishing with 1500 paper and then rubbing compound and Mirror Glaze #7 and #6 and you will be surprised what you can fix.

Posted: 12 Jun 2006 3:59 pm
by J Hill
There was a 'Dave' who said he'd send pictures. I think there's some confusion about who wants pictures of what.

Posted: 12 Jun 2006 10:49 pm
by Dave Boothroyd
I have sent a set of pictures in a powerpoint presentation to Mike D.
If anyone else would like to see it, let me know.
If anyone knows how to put it on here, please do so .
It shows stages in the process of making a seven string, cat can style lap steel for an African friend.
I just wish that I'd had the time to put another couple of coats of lacquer on it before it went to Dakar.
Cheers
Dave