Official Luthiers Forum!

Some of you may remember that I am a bit of a noob at this and a while ago I posted a 'Hi all' post on this forum.

I was told then that if something goes wrong to walk away and post messages and to ask questions and most importantly to not panic:) Well.........

I Have bought a StewMac 000 kit about 4 weeks ago.
I have been taking my time and thoroughly enjoying my build. I honestly do not know why I havent gotten into this before it really is amazing:)

I have put the sides together and installed the neck and tail blocks. I have made a waist clamp and inner maold and installed the kerfed linings (backside and topside). I have also installed and scraped down the rosette. I have made a sanding board with 1.5 degree and 5 degree wedges to get the right curvatures when sanding them top and back kerfed linings.

Today I have started to sand the topside kerfed linings. Even though I have taken my time I have somehow managed to take too much material away from a small section of the topside sides.

The area in question is the top right bout of the guitar when looking from the topside.

The deviation between the normal sides and the area I have taken too much material away from when using a square is about 1mm maximum deviation over a distance of about 15mm (approx. 0.04 inch deviation over 0.6 inch length)

I have pictures but i do not kno how to link to them.
(I do subscribe to a photo web host service though!)

Is this a problem?
If so how much of a problem?
Also, if it is a problem is there a way of rectifying it?

Thanks for helping and your patience.

Barry.

Barry,

Panic not.

I'm not sure I fully understand your problem. A picture would help - use the image upload icon where you post (it's the next to last one).

If you have just sanded the lining and part of the side down by 1mm too much over a short secton of the kerfed lining this should be easily fixable by gluing a thin strip (mahogany if that is what the linings are) onto the top of the linings there and re-sanding down to the correct profile. The fact that the sides are a tad low here and it is the strip is not a problem as when the top is glued on you will rout this away anyway to install the binding.

If this isn't the problem there will be another easy fix once we understand it.

Onwards an upwards Dave White38967.6266319444

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Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010

I am not sure exactly what you are saying, but let me tell you how I do it. I think it might help you.

I sand the top on a FLAT surface after the linings are in, then I elevate the heel block .150" inch with a stick sanded to that size. I mark the headblock and the linings down to the widest part of the upper bout and sand ONLY that area on the flat surface until all the marks are gone.

This helps flatten the area where the fb lies.

Once the top is on you want to be able to put a straight edge on the area where the fb lies and see a gap above where the saddle of the bridge will set of about 3/32". The geometry of every guitar is a little different, so you may need to adjust this a little, but I have built that guitar with these specs and it worked out well.

Did this help?

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

Barry, if your pictures are already on the net, just use the photo button above, (the tree without the arrow) and put the URL for your pics including the filename & extension in the box.
It will definately be easier to help with your question if you have pictures.
Initially without exactly what you mean, I would say just sort of spread the error over the whole of the upper bout or just make the guitar thinner but the amount of the error, 1mm. I can't really envision how you are using these sanding board and wedges since I use radiused dishes for mine.

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Tickle your guitar daily, and it'll tickle you back.

Guys,
Thanks so much for the information so far. It really is appraciated.
Once you see the picture (which hopefully I have uploaded ok) I think you will all agree that the suggestion of leaving it be is the best (I hope).
I think that this slight error will be 'hidden' after routing and binding installation.......i think:0

Onwards and upwards indeed...phew:)

Ok, I am assuming that in an area you have sanded down a bit past your desired profile. and that you were using the StewMack guild books sanding board to sand the kerfing to profile. No reason to panic 1mm in .039" just over 1/32". this is nothing in the hole schem of things.

First thing is that the top is pretty much one continious flat plane at the the edges of rim. It is pretty simple to level this plane back out and 1/32" will not affect any fit up enough to matter. So just sand the top back to a single flat plane with about 2 degrees of incline on the linings.

Second thing that crosses my mind is that the top's arc should be 25-30' radius that is 1.8-2.3 degree slope at the linings not 5 degree. 5 degree sanding block is for the back which has a 15' to 20' radius. I thought i remembered the StewMac instruction telling you to build a sanding board with 5 deg on one side and 2 deg on the other. one side for the back the other side for the top.MichaelP38967.6473958333

Not a big deal. Though you are profiling the sides the hard way. Just patch in a thin strip of wood the width of the kerfed linings and then re-level things to get it all flat again. As was said before, it's going to get cut off in the binding process anyway. but you want something under the top so it has something to glue to.

Thanks guys,
I would prefer to be able to simply keep the effected area and see it all come good when i rout the binding channels and install the bindings.

If you guys think that this is a bit shoddy I will of course go the extra mile and glue in some mahogony (I have some scrap in the kit) and re-sand back to the correct level.
Although i think the 15mm length, which is of course tapered, will maybe prove to be not too troublesome when glueing the top.

MichaelP
The StewMac kit indeed instructs you to make a sanding board with a 5 degree wedge on one side for the back and a 1.5 degree wedge on the other side for the top. I have made this and and I have been using it to create my profile. Ie 1.5 degrees for the top

I plan for my next guitar (see I was warned about this happening a few weeks ago when I joined the forum:)) to get sanding dishes made by our very well equip eingineering solutions department in work.

snood38967.6633564815

Barry,
This sort of thing happens quite frequently when learning. One easy way to fix it, is to chisel away the kerfing in that area, and just install some new kerfing and leave it proud so that the top can be glued to it. When you glue on the new kerfing in that area, leave it more proud than the rest of the kerfing and then sand down again checking your progress more often. It should be covered by the binding anyway. Good luck!
Tracy

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Tracy
http://www.luthiersuppliers.com

The only concern I would have is that the top meet and have good contact with the linings in that area. A failure to contact the linings in even a small area will create a shear path of failure for the top to lining joint. the fact that the side rim is a little low is no issue. You could remove the lining in the effected area replace a tad high and sand down to desired height. this eliminates the path of failure for the top/lining glue joint.

Ah
Thanks Luthier Supplier.
A great work around. You guys weren't kidding where you when you said, 'if it goes wrong, stop and come back to the forum. Most things have been done before and a fix will almost certainly be available.'

I have three choices now:
1 Chisel and remove the kerfed lining in the problem area and re-install some new linings leaving them slightly proud and re-sand level.
2 Leave it and hope the routing and binding install will take care of things.
3 Glue in some new wood and re-sand.

I think I like 1 best as long as I do not damage the sides but 2 of course is less work.

I would appreciate thoughts on which route I should take. I am guessig #1 but we shall see.

Once agian thanks to you all for your help it is very appreciated

[QUOTE=snood] Ah
Thanks Luthier Supplier.
A great work around. You guys weren't kidding where you when you said, 'if it goes wrong, stop and come back to the forum. Most things have been done before and a fix will almost certainly be available.'

I have three choices now:
1 Chisel and remove the kerfed lining in the problem area and re-install some new linings leaving them slightly proud and re-sand level.
2 Leave it and hope the routing and binding install will take care of things.
3 Glue in some new wood and re-sand.

I think I like 1 best as long as I do not damage the sides but 2 of course is less work.

I would appreciate thoughts on which route I should take. I am guessig #1 but we shall see.

Once agian thanks to you all for your help it is very appreciated [/QUOTE]

Your not going to damage the sides when you remove the linings. You will be amazed how easy it is to chisel them out. I am assuming that the linings are mahogany triangle type linings. they carve like butter but even if they are revers it still no issue

Ok
Thanks everybody for all your help.
I will chisel out the linings over the affected area and re-install new linings and re-sand.
Thanks
Barry.

Barry,
Your welcome! You don't have to chisel off the whole lining, just the area that is too low. Since it is on the top side, no one will be able to see the seams unless they look really good. I do wish you luck! Seems like you have a good handle on it.
Tracy

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Tracy
http://www.luthiersuppliers.com

Thanks.
I do not understand what you mean regarding your comments on the seams?

What I mean is that if you chisel off just the area of the kerfing that is the problem, then you will have to splice in a new piece of kerfing. This new piece will butt up against the existing kerfing. That is the seam I'm referring to. But if you are using triangle kerfing, then it will be less noticeable than reverse kerfing. Hope that helps. Good luck!
Tracy

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Tracy
http://www.luthiersuppliers.com

Yep, I had to chisel mine out too...first kit build. It's nothing, they'll pop right out. Just remember to clean them up very well for the new glue to adhere to.

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