Potato Chip

[Ray Ussery]

I won't go into detail because...well... BECAUSE...but when I first started with acoustics or at least tried to...I bought two kits from one of Ken's competitors and I was taken badly...but truth being, I didn't know any better.

Hanging in here with Ken and the rest of you, I feel a bit more enlightened. I THINK I mentioned it before but one of the kits included a badly "Potato chipped" top. I played with it for a year....watching it and the humidity, I finally exposed it to 60% when the Monsoons came thru last summer and it flattened out. But that won't do in this climate where the average humidity (Except for rare occasions is 20-25%.

The top was braced. I got to looking at it closely and to me...it was a really poor job. I was told "Martin" did it. Maybe they did...but I doubt it. Ive seen, owned and played a LOT of Martins and never saw any of this sloppy workmanship...I THINK the seller braced it. I took hold of the cross braces, just looking and they popped off in my hand...almost NO glue...I got PO'ed and ripped the REST of the braces off...only two were really glued and the bridge plate....I left only the bridge plate...and cleaned up the rest. It's a pretty nice top...measures off at .114 WAY too stiff for that...and after a week of weight...it's still potato chipped with the outside edges turned up to about a 12' radius across the lower bout...I believe it's Sitka.

My question is: How can I straighten this out so I can re-brace it to the proper contour...OR is it necessary prior to bracing? It would seem to me that it would put a lot of pressure on it to go from 12'R one way to 16'R the OTHER way...

Hope I'm clear on the problem... I can do a pic if necessary...or do I need to just trash the thing and buy another top...I've got a fair amount into it already would like to save it if possible.

Thanks for your comments,
Ray

[ken cierp]

Check to see how far off the grain is to vertical – look around the sound hole as well as the neck and tail block areas. If the angle is not close to 90 degrees I would not mess with it. Given that a nice Sitka top can be purchased for under $25 the decision to use or not has a lot to do with your expectations – it may be just fine after bracing but I’d thin it down a little. Another thing to consider is, if the top was not braced with a traditional pattern, the top likely was not at least AA to begin. Those tops from Martin with Modified X and A are rejects from the lower priced models.

[TonyinNYC]

If it were not joined, you could pop it in the oven at 200*F clamped flat between some wood dowels or anything to keep it flat. Then after about 20 minutes, take it out and let it cool. However, since it is joined, that process will pop the glue joint in the center.

If it is the edges bending more than the center, you could try to use your wife's clothing iron, set hot with no steam. I have never tried this, but I have heard of it working with warped hardwoods. You are basically bending the wood like you would with a hot pipe or blanket. The most important thing to remember when using a clothing iron to flatten wood is to never, EVER do it when your wife is home. For some reason, using the iron on wood gets them mad. I steamed out a couple of dings on sound boards over the years and each time, my wife gets mad thinking I am going to ruin the iron. I have so far, escaped ruining it.

[Ray Ussery]

Ken:

The grain is exactly vertical, or 90 degrees all the way around...there is no run-out on the parameter...all the grain is straight...however it is a "Modified X" braced guitar...I don't like that..would like to change it but? I can fill the groves in the heel block and add some additional wood underneath the "L" to compensate but? would that work? and then brace it with the traditional forward shifted "X" bracing of the late 30's?
I haven't really checked the blocks...other than they LOOK like just pieces of plywood? maybe they aren't glued any better than the bracing was.. (It came already bent and cut to profile with the blocks glued in place...it's Mahogany...the sides are nothing special...they have a couple of repaired cracks that you can't see on the outside...the back has a nice grain pattern but again...it's nothing special... :>)

On THIS one...I got the top, sides, heel and tail blocks and neck for $100...but that's all I got...have to acquire the rest....fingerboard, bolt for the neck...back bracing, purfling, binding, tuners, bridge, saddle, nut, and frets etc...I guess it would could be a good practice guitar and learning lesson ..then again, maybe it's not worth the effort...I think it will cost a good deal in the long run...I REALLY got hosed on the other one, but that's another story...Appreciate your help and comments Ken...any other input you may have will be taken seriously to be sure...

Ray

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Tony:

You are at LEAST a half a bubble off...hehehe...anyway I'll have you know I have my OWN iron...see....I ruined the surface of HER iron (Discolored it) and was forced to buy another so she threw the other one at me and I caught it...hid it...until I got my shop enclosed then stashed it for a while...and now she's forgotten all about it....thinks I bought it at a yard sale...once in a while I steam out a dink in furniture of something and she says "I'm glad you don't use MY iron that way)...hehehehe ...see? well... another 20 years of married life and you'll learn more of the tricks..(IF you LIVE that long). I did think about the steam iron though...just for fun I may try that if there's no other way....thanks Tony, you know I'm teasing you!...IF not you're on you're own...HAHAHA!

Ray

[ken cierp]

Its important to remember that the wood is going to always seek to be "its normalized shape" based on ambient humidity. So my point would be that the braces are to a certain extent, reshaping the sound-board, flattening with heat or weight generally is not perminent. The bracing needs to be beefy enough and the sound board flexable enough (thinned) as to not "distort the braces". Hope that makes sense. Also don't forget that the string tension is going to "pull" the top into an unnatural state as well. The sound-board is a diaphragm perfectly flat is not a requirement.

[Ray Ussery]

I understand Ken, I'm going to play with it... thin it out, see how it looks then and go from there...be talking to you soon!
And thanks!
Ray

[TonyinNYC]

So it seems, Ray, that you are suggesting I use my wife's iron, ruin it, and then claim it as my own? Sort of like marking my territory but by staining the iron? I like the way you think.