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  #1  
Old 04-18-2017, 05:45 AM
SnowManSnow SnowManSnow is offline
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Default Securing a top / back for thickness

How do you guys secure your top or back for thicknessing with a plane?? I've clamped it on the sides and it ends up scooting around eventually and causing issues. I can't use a stop board at the front because the hand plane will hit it...
Just clamp it harder?
I'm also facing the reality that i need a VERY sturdy table for this.. .which is a no brainer, but something you don't think of until you experience needing one.
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  #2  
Old 04-18-2017, 06:05 AM
B. Howard B. Howard is offline
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I just use two cam clamps and move them around so they are not in the way....

Sounds like your plane is in need of a good tuning and sharpening though if it is grabbing and not cutting.
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  #3  
Old 04-18-2017, 07:13 AM
redir redir is offline
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Picture = 1000 words. Pencil marks act as a guide. MDF backing is nice and flat. The cauls are lined with cork, doesn't take much pressure to hold at all.

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  #4  
Old 04-18-2017, 08:06 AM
SnowManSnow SnowManSnow is offline
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thank you.
and yes I believe my iron may need sharpening.. the sole is good and flat, so thats nice.
I also think a lot of it has to do with me just learning how to manipulate the plane. It did get a good bit better once I figured out the weight distribution front to back.
And yes, the pick is great thank you sir.
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  #5  
Old 04-18-2017, 08:48 AM
charles Tauber charles Tauber is offline
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I've posted this before, but it seems relevant to repeat here. It shows my setup, pretty much the same as redir's:

https://www.youtube.com/watch?v=maJCqbtN-6I

A couple of notes that might be helpful:

1. plane/smooth the face/bookmatched side and then remove the remaining excess from the side you don't see (i.e. the inside of the top or back). That is what is demonstrated in the video. (Note the card scraper is dull, but I didn't want to stop the filming to sharpen it. Most of the work had already been done, and these last few strokes were for filming purposes.)

2. for tops, inlay the rosette after smoothing the bookmatched face, glue in the rosette, level the rosette, then remove the excess top thickness from the inside face. Then cut out the soundhole.

3. unless your top or back has zero runout, if planning in the direction of the grain (longitudinally), the grain direction changes from one half to the other. If planning along the grain - as opposed to across the grain - you will likely need to plane each half, after joining, in the opposite direction. A swipe with the plane will tell you which direction is the right one. The directions will reverse when planning the inside surfaces. To plane the other half, I simply un-clamp, rotate by 180 degrees, re-clamp and carry on.

4. In the video, above, I have 2 mm worth of zircote to waste: I am using a very coarse plane setting - thick shavings. As you get closer to the final thickness, final passes, particularly on soft top woods, are paper thin, or less. In the video, I'm using a bevel-up jack plane, but could have just as readily used a 4-1/2 smoothing plane: the jack plane was already sharp, so I used it.

5. Generally, edge tools require sharpening each time you use them, and sometimes, mid-job, depending on the job. (Zircote is tough on edge tools.)

6. If using a plane for thicknessing, a blade (iron) that is honed square across its width, the ends of the blade will leave plane "tracks" between strokes. One way to eliminate that is to camber the cutting edge so that it has a slight curvature from the center to the edges, about 1/32". With practice and skill, for many applications, you can go from plane to finish, with no need for sanding or scraping. Another way to eliminate the tracks is a card scraper. Another way is sanding. All of them will work.
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Old 04-18-2017, 10:22 AM
SnowManSnow SnowManSnow is offline
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thank you so much charles
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  #7  
Old 04-18-2017, 12:22 PM
Alan Carruth Alan Carruth is offline
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I always try to clamp the two near corners, and plane away from the clamps. That way there's no buckling of the top. It's a drag when that happens...

I use two 'C' clamps, with a small piece on Masonite on the top to spread the force so it won't dent. Plane the far end on one surface for a while, and swap ends. Once you've got one side about half smoothed out, turn it over and do the same on the other surface. Then go back and level the first surface.

You have to hit the entire surface equally to get it level. There are only two ways to be sure of doing that: you can either be perfectly random or perfectly organized. Nobody can be perfectly random.

I do as Cumpiano says; plane at a 45 degree angle across the surface with strokes that are side by side. Go left to right on one pass, then right to left, so that the plane strokes are crossing each other at right angles. Plane over the whole surface every time, even if you're not removing material over a wide area.

Don't even think of doing this with a dull plane; you can't take a light enough cut with a dull one. Properly done on a flat surface you can get the whole thing to the same thickness within a few thousandths of an inch.
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Old 04-18-2017, 12:37 PM
charles Tauber charles Tauber is offline
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Quote:
Originally Posted by Alan Carruth View Post
... you can get the whole thing to the same thickness within a few thousandths of an inch.
Which requires that you have tools for measuring it. Should be obvious, but worth mentioning. You can buy a deep-throated calliper for instrument making, or you can make your own with a $25 dial indicator and a wood or plywood "frame".



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  #9  
Old 04-18-2017, 12:49 PM
SnowManSnow SnowManSnow is offline
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I know some folks don't understand what I'm about to say, but, I'm a visual tactile type learner.. I can read a book on something and not get it, but if i can see it.. or fiddle with it.. I'm on my way.. again, thank you so much for the pics Charles.

Yes, I was debating how best to create something like that.. I also wondered if there was a magnetic type that the gauge would "suck to" a magnet on the other side, and allow you to just move it around.
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  #10  
Old 04-18-2017, 01:07 PM
charles Tauber charles Tauber is offline
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Quote:
Originally Posted by SnowManSnow View Post
I also wondered if there was a magnetic type that the gauge would "suck to" a magnet on the other side, and allow you to just move it around.
There are a few gauges used for measuring plate thickness on finished instruments, though they are fairly expensive. They allow thickness measurements where you only have access to one side of the plate.

Probably, one could design a gauge that is magnetic, as you describe. Chances are that it wouldn't work better, or be less expensive than a $25 dial indicator in a frame. Sometimes it's fun to design a better mouse trap: other times, when you just want the mouse trapped, it is more efficient to just use a proven, ready-made trap. Depends upon one's focus and interests.
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  #11  
Old 04-19-2017, 06:27 AM
Truckjohn Truckjohn is offline
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Before you go make your own micrometers.... Check out "sheet metal micrometer" on Ebay and your favorite used tool places.

I got a 12" throat, 0-1" deep sheet metal mic used for around $15.00 a couple years ago. Granted - it wasnt a premium brand name... But its still worlds better than only being able to measure 1" inside the edges....

Also - if you plan to thickness plane your plates - consider making yourself a toothing plane iron. You take a standard replacement iron (cheap at the hardware store) and slot it 1/16" to 1/8" deep at the cutting edge with your dremel. Sharpen it up good and viola! For rough thickness work where you want a nice deep cut with way less effort. Its way easier to push a tooth iron in hardwoods than it is to get anything close to the same cut depth with a standard iron.

Thanks
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  #12  
Old 04-19-2017, 11:48 AM
Alan Carruth Alan Carruth is offline
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Note that the slots in a toothed iron are made on the flat side of the cutter, not in the bevel. They don't need to be very deep or wide either. I've made a couple of toothed irons by making cuts parallel with the length of the iron about 1/32" deep and 1/8" apart using a hobby shop razor saw. It's a lot easier if you can work on the iron in the annealed condition, of course, which is what I did, but then you will need to heat treat the iron to make it hard and temper it.
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  #13  
Old 04-19-2017, 05:51 PM
dekutree64 dekutree64 is offline
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One cam clamp to hold it, another as a stop. Plane pointed straight across the grain, but moving at 45 degrees. 4 notches ground into the blade with a dremel wheel to give it some large teeth. Cuts easier than a full width blade.

I sit on top of the table to eliminate the stability problem Otherwise you either need it to be extremely heavy, or extremely stiff and attached to the floor/wall to complete the "circuit" from the wood, to the plane, to your feet, to the table, and back to the wood.
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  #14  
Old 04-19-2017, 06:34 PM
mirwa mirwa is offline
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I just use double sided tape

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