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Hi! Being brand new and about to start my first build, I would like to hear your input regarding different techniques and their pros and cons...mostly sanding versus planing and using a 90deg versus 45 deg joint.

Thank you!


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i remember that dilemma, being relatively new to this too. i use a plane and aim for a 90º joint (i suppose i don´t get it exactly at 90º). using the plane is more comfortable, produces less dust and should give you a better gluing surface.
using a plane it could be a bit trickier to get that perfect joint, but it´s a knowledge that really pays off having, IMHO. a sharp and well tuned plane does help a lot. i used some B-grade tops and just went for an afternoon of jointing until i felt like i had the basics relatively covered.

good luck!

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member of the guild of professional dilettantes

I prefer planing to sanding, the consensus seems to be it gives the best glue joint.
As to the 45 vs 90 degree joint, I'm a 90 degree man.
I can see the possible logic of more surface area with 45 degrees, but I prefer to candle the joint (bright light behind the unglued joint) before gluing - best way to check the fit.
I don't see any way to check a 45 degree joint for a perfect fit before gluing, and clamping could also be problematic.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

http://farm8.staticflickr.com/7148/6767 ... 00d6_z.jpg
This is not my picture, but it is the way I and many others glue up plates. I use 4 cross bars, some use 3.
Very easy to use, and puts on tons of pressure........................pardon the pun.
Have never heard of using a 45 degree joint for plates.
Tom

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A person who has never made a mistake has never made anything!!!

I am a newbie too. I have use a long plane and a shooting board with very good results. See:

http://www.obrienguitars.com/videos/
The Shooting Board
#33 - 06:38

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EddieLee

The 45 degree joint does sound interesting. Anyone try it?

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Joe Beaver
Maker of Sawdust

My opinion is that doing 45 degrees makes it way more complicated. For me I use the K.I.S.S. method. Even then things are hard enough, no need to make them harder. But I may be way off base and there may be some simple way to do 45 degrees.
Tom

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A person who has never made a mistake has never made anything!!!

90s are simple and has been around since hide glue was invented and works just fine...so why go be complicating a simple joint with 45s? Hmmm?

Glue works best on smooth surfaces from planning...sanded surfaces are rough. Rough surfaces bind better with cement not glue.
So the only reason to be sanding yer joints would be if you gonna be using something like portand cement, which is messy, heavy and really don't bond to wood all that well anyways. You getting the idea now?

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Audiences and dispensations on Thursdays ~ by appointment only.


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So how come braces and soundboards tend to stick together without too many problems , when both of the contact surfaces have been sanded rather than planed?

For $60, the Easy Jointer from Luthier Suppliers is a good bet. Kathy Matsushita demos one on her website here. Depending on how committed you are to continuing after you're first, this could be a fool proof, inexpensive entry.

I use a #5 Lie-Nielsen plane, shooting board, and really like LMI's plate joining jig, though I used the tape method and hide glue for all but my current project.

Using a plane is going to be a bit more expensive: you'll have the cost of plane, and some sharpening gear. You'll also need to learn to use the plane. It's pretty easy, but it takes an afternoon or so to figure out how to adjust your pressure when the joint gets convex or concave. That said, it's the more versatile tool and skill set to have in your arsenal.

It is critical if you want to make a great joint. Sharpening and planing skills will go a long way for you. And after you become proficient at them, (doesn't take long) you will feel like you are on a different woodworking level!

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Pat

Todd, lemme ask you...do the undersides of your soundboards and the top (glued) surfaces of your soundboard braces receive their final treatment prior to glue-up from a handplane or a sander ?

If sanding is good enough for Kathy I would think it would be just fine. She is well known and her guitars arent cheap. Then theres the fact that many of us sand brace profiles then glue as well as sides before glueing the top/back on.

Using a sharp Plane to joint a Soundboard or a Back is basic stuff. It's actually pretty easy. Any Guitar maker worth calling himself such should be able to wield a jointing Plane. In fact I don't understand why anyone would avoid using one.

My small hands have problems getting a perfect planed joint with a larger plane. I end up chasing gaps for a long time and it hasn't gotten better with several guitar and uke builds. It seems I often have to end up going to the easy jointer (which I bought before i knew that a planed edge is superior for the joint). So…have been looking at the Veritas Shooting Plane and thinking that if I modify my Todd Stock shooting board to add the outer edge of plywood, making a straight tight track for the plane, I might have a really easy time of it. It's big bucks but may be worth it. Anyone have an opinion on that?

Not used one personally, but here's a recent review from Oz.
http://www.inthewoodshop.com/ToolReviews/LVShootingPlane.html
Comment at the end is

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

why? because of flatness, or some issue with "tooth" of the grain, etc...?

cool. not challenging, just clarifying, thanks. i myself only own one joke/toy hand plane, so i'd be inclined to sand with a long bar(if i were an acoustic guy joining back planks)

A perfectly planed joint is worth striving for, but if you must sand, using a back graft and an inlay strip can add a lot of strength and hide a poorly executed joint. For soundboards the joint needs to fit perfectly below the soundhole and moderately well above the soundhole (under the fingerboard), but obviously the soundhole area doesn't matter. Keeping that in mind can save some aggravation.

Everyone should have at least one well tuned handplane. If for no other reason than the joy of making wood shavings.

What about a lap joint? Anyone ever tried that? I did once but it was a PIA. I think it would be a superior joint though.

your brace width tends to be 2 to 3 times wider then your soundboard thickness (i hope) -much more contact area.

fwiw i use a shooting board and a plane. i candle (lightbulb actually) and rub the joint (reveals highspots) and scrape. easy, fast, and final.

board joints are the most critical joints on the guitar and this is one area where you need to be a craftsman. sure sandpaper will "work" and so will the sidewalk, but is it really craftmanship?

I've seen braces out of Ovations where the glue surface still had saw marks on it, and they were holding up. Would you say saw marks on brace gluing surfaces are OK on that basis?

When I was working with Carleen Hutchins she talked about a study that was done back in WWII by the Forest Products Lab of the USDA on glue joints. Back then they still used a lot wooden airplane propellers, and some of them were coming unglued. This is an issue when you're at 10,000 feet, and even more of one when you're at 200 feet in the climb out. They looked at the way the props were made, and found that the ones that had the pieces sanded to thickness before lamination tended to fail, where the ones that were thicknessed with sharp planers did not. All the manufacturers were made to switch over.

I've never seen a center joint in a top that was planed to 45 degrees. It makes some sense in theory, but not in practice.

I've done all of my jointing for more than 40 years with a Record #4 smooth plane. I had a lot of trouble at first, too, until I found out about how to tune a plane. Once I did that it got much better. That's not saying there are never any problems, but a well tuned plane that's really sharp and good technique will minimize those. I can usually get the joint right in about the time it takes the hide glue to warm up.

When will Stew-Mac come out with a micro-biscuit joiner?

45° is a bit extreme, but it doesn't need to be EXACTLY 90° either...
If you align the plates and plane both at the same time, the joint can be a couple of degrees off 90°. Of course, they need to be off the same amount and in the same direction, so you must plane them both at the same time with the bookmatch "closed".

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A man hears what he wants to hear, and disreguards the rest. Paul Simon

LOL ....arie, as well you know by now, I like to come out of left field on a lot of these discussions.

Just FTR, I personally am also able to plane a perfect joint with my crap Stanley plane (on which I have spent far too much time tuning ...I should just get a Lie Nielsen) but as has been mentioned earlier, a well tuned plane , a razor sharp iron, and a nicely constructed shooting board will get you there every time.

However....as you well know, I manufacture and sell precision ground sanding beams which are dead straight, dead flat. These are sold for the purposes of fret leveling...I do not advocate them for any other purpose.

Nonetheless I have had several emails from customers ( amateurs and enthusiasts , admittedly) over the years who have adapted the beam for the purpose of giving a final stroke to a soundboard edge which they had planed but just couldn't get quite 100%. One stroke of the beam on either edge , usually with with 400g PSA paper, (although a couple of people used 600g) was enough to render the joint "candle proof" .

So, on the molecular level, do I believe that sanding an edge with a dead square , dead straight, dead flat sanding beam with a high quality 400g abrasive will nevertheless lead to premature joint failure ? No, I do not. Like I say, I don't do it myself, because I don't need to, but I have no reason to doubt that it produces a joint which will equal the longevity of a joint which has come straight off the plane.

The "criticality" of the soundboard joint, is something else on which I feel I should touch ...as mentioned in an earlier post , the joint only needs to be perfect from the soundhole to the endblock ...so we are talking what ...11 1/2" max" ???

Once the soundboard is braced, and the guitar assembled, then the joint is receiving support from the X brace joint, the bridge and bridgeplate, both of the tone bars, and the end block. Above the soundhole we have the UTB the neck block, and possibly a popsicle brace as well. The rosette also adds strength. That sucker has more support than a blind single mother on welfare.

I am sorely puzzled by Todd's revelation that he gets inundated by guitars with soundboard joint failure, and I cannot account for it. I am assuming that the guitars he gets in for repair are constructed by inexperienced builders , and that for some reason there are a lot of inexperienced builders in the state of Maryland.

Oh what I wouldn't give to have Todd Stock in a Box!!! Todd...we have sunshine year round down here, and a room just for you...please be in my Christmas stocking