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  #31  
Old 02-06-2021, 02:42 AM
Talldad Talldad is offline
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At this point, if you are likely to build two guitars, it would be a good idea to place a 1kg 2lb weight on the centre of the board which is supported on the sides to measure its deflection. You could then support it too and bottom and measure again.

There’s no right answer but the stiffness of the board greatly affects tone, if you have a measure you can use it to inform your next build.
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  #32  
Old 02-06-2021, 10:30 AM
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warfrat73 warfrat73 is offline
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So I resharpened the plane blade, as sharp as I know how/am able with current equipment. Reconfirmed apparent grain orientation and immediately got tear out again... looks like I'm dealing with interlocking grain.

Cumpiano recommends planing diagonally. Tried that. Got marginally better results. I have to roughly reduce the back by half. I'm thinking there must be a better strategy. Belt sander for bulk removal and then scraper?

One suggestion I saw online was to make/use a higher angle plane blade (basically grind a back bevel on a spare blade).

Alternatively, I did manage to get the EIR back flat enough that I can work with it by spraying it down and putting some weight on it.

Suggestions welcome.


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  #33  
Old 02-06-2021, 11:13 AM
charles Tauber charles Tauber is offline
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Some years ago, I spent a couple of weeks with Rob Cosman, who is all about hand tools. It is his contention that 95+% of wood can be successfully hand planed without significant tear-out. It had been my experience, much like yours, that many woods didn't take kindly to hand planing.

We were making a Shaker lap desk in which only hand tools were used from rough lumber to finished piece - no sandpaper, no scrapers, no machines. To cut to the chase - pun intended - I had a piece of wood that, when planed, would tear. He suggested I close the throat on the plane to "zero". So, I adjusted the plane to "zero" throat, planed some more and then showed him, triumphantly, that there was still tear-out. He examined my plane and said, "That isn't zero", then proceeded to alter the throat clearance until it was no more than, literally, a hair's space. Back I went to planing and there was no tear-out.

The point of my story is that one of several things one can do to minimize tear-out is change the amount of throat clearance. The clearance needs to be sufficient to allow the chip being cut through the throat, but no more. That means for heavier cuts, more throat gap, for lighter cuts, less throat gap.

Different styles/designs of planes have different means of adjusting the throat. Bevel-down planes often require loosening the two screws that hold the frog and then sliding the frog forward or back. It can be cumbersome to get right where you want it.

Other styles of planes, particularly bevel-up types, allow the throat to be adjusted directly by tightening and loosening a knob. Being able to do so, is one possible advantage to bevel-up planes.

Adjusting the throat can go a long way towards reducing tear-out. Other things include changing the effective cutting angle - either by changing the bevel angle of the blade, by using a steeper frog or by using a bevel-up plane that will give a much lower cutting/bedding angle. Depending on the wood, sometimes a much steeper cutting angle is better, sometimes much shallower.

Another approach is to use a toothed blade. Another is to plane across the grain - not just at an angle, but 90 degrees to the grain. If you do that, be careful of unsupported wood at the far edge as the plane leaves the wood.

The brute force approach is, as you suggest, to leave lots of thickness to sand/scrape to the bottom of the tear-out. A belt sander might work, but might be difficult to control for thickness and you might spend just as much time sanding/scraping the irregularities as dealing with the tear-out.

Also, I find it easier to hand plane the back after the two halves are glued together, still in rectangular form, not cut to guitar shape, than to plane the two halves before they are joined. (Ditto for the top.)

Last edited by charles Tauber; 02-06-2021 at 11:20 AM.
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  #34  
Old 02-06-2021, 05:19 PM
phavriluk phavriluk is offline
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I'm suggesting that OP get out his RO sander and his thickness measuring tools and see what happens. Planing may well be more a nuanced skill than is needed right now. What's needed are b/s ready to mold, join, and shape. I think maybe time spent with a plane might be better spent with the sander. Won't hurt to see.
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  #35  
Old 02-06-2021, 05:33 PM
charles Tauber charles Tauber is offline
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I think it depends upon the op’s purpose: to learn how to use hand tools commonly used to make guitars and employ them in making a guitar or to have a finished guitar.

There are lots of ways to accomplish the task, many of which will work. What experience does the op want to have? The experience will largely be influenced by the methods used.
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  #36  
Old 02-06-2021, 07:23 PM
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warfrat73 warfrat73 is offline
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I'm going to try closing down the throat, and then planing perpendicular to the grain, per Charles' recommendation.

If I still struggle with that, I'll go to the sand paper and see what happens... and work on refining my sharpening and set up skills.

My goal here, as I've suggested before, is primarily to learn and secondarily to build a guitar--though these are hard to separate (previous comments that other folks interpreted as setting myself up for failure I imagined as prioritizing the learning process).

I'd like to be able to confidently build a guitar every year or so. If not for the pandemic I'd have thought more seriously about taking a class. But I have no designs on building professionally.
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  #37  
Old 02-07-2021, 05:11 AM
nikpearson nikpearson is offline
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Default Steeper bevel angle, tighter mouth, toothed blade, cabinet scraper plane...

I’ve found that a bevel-up plane is very useful in these situations as you can easily swap a spare blade in with a higher bevel angle. For that type of wood I’d use a 50 degree bevel (or micro bevel) which when combined with low angle bed of 12 degrees produces a 62 degree angle - closer to scraping than planing. You can add a steeper bevel to you existing blade and then grind it back out after you’re done, but blades aren’t very expensive so it’s good to have at least one spare and set up that way.

Toothed blades allow you to hog away wood much quicker but you’ll likely still need to plane smooth with a high angle blade afterwards. As Charles suggested keep the plane mouth very tight to support the wood and avoid tear out.

I’d avoid planing perpendicular to the grain but diagonally can help at times.

You can achieve a similar result with a standard bevel-down plane by adding a back bevel. Again, better to make use of a spare blade. I’ve used low-angle bevel up planes almost exclusively for the years because they just seem more versatile, are quicker to set up, change blades, etc. A low-angle jack and block plane will cover nearly all guitar making tasks. I’d always choose low-angle models because they can double or triple up as standard and high angle planes by swapping blades with different bevel angles.

If the wood is still causing problems (and you don’t have access to a drum sander) then a cabinet scraper plane will work on even the most figured and tricky woods. They’re not expensive and can prove very useful for other jobs. I often use mine for final smoothing of figured woods.

Hope that helps.
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  #38  
Old 02-17-2021, 11:18 PM
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warfrat73 warfrat73 is offline
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Well, I've made a little bit of "progress." But taking this back down from ~.2 to ~.105 by hand is taking some time. Several hours of working at it (and also fiddling with the plane to try to avoid tearout, and resharpening) and I'm down to ~.13. And I haven't even started on the sides yet.

I also scraped the face side and got that pretty well cleaned up.

The guy I bought it from on eBay offered free thickness sanding to spec. I'm sure regretting not taking him up on it right now.

I thing I'll get a bit more aggressive with it over the weekend and not worry too much about tearout until I'm a little closer to spec, and then clean it up with the craper. Probably be faster.
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  #39  
Old 02-18-2021, 08:08 AM
DickHutchings DickHutchings is offline
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I wish you luck but this is exactly why I bit the bullet and bought a brand new Performax 19x38 drum sander. I haven't regretted it at all. It comes in handy for making bindings as well.
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  #40  
Old 02-18-2021, 10:13 AM
charles Tauber charles Tauber is offline
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Quote:
Originally Posted by warfrat73 View Post
The guy I bought it from on eBay offered free thickness sanding to spec. I'm sure regretting not taking him up on it right now.
Actually, you might be glad that you didn't. This way, you get first-hand experience of working hard, difficult wood with planes and scrapers.

In the future, you might prefer to thickness sand, but at least you have a taste of an alternative hand tool approach.

Quote:
Originally Posted by DickHutchings View Post
I wish you luck but this is exactly why I bit the bullet and bought a brand new Performax 19x38 drum sander. I haven't regretted it at all. It comes in handy for making bindings as well.
I did much the same thing. However, as I took classes and learned how to better use hand planes, these days, I prefer to do much of the back and side - and all of my top - thicknessing with hand planes. Some woods don't sand well - the resins gum up the sandpaper very quickly - and it can be faster to hand plane them.

A larger, heavier hand plane can sometimes help with hard, difficult woods: the extra mass helps. In extreme cases, with a lot of wood to remove, a scrub plane can also be used, as an alternative to a toothed blade.

Bindings, and solid linings, are much easier to make using a thickness sander. Bridge plates and head veneers, too. And nuts and saddles and...

In "the old days", the only thickness sanders available were wide-belt industrial machines at prices few individual luthiers could afford. Many individual luthiers, including me, made their own. Now there are a variety of drum thickness sanders available, some under $1k. I happily junked my home-made one for a commercial one with self-feed and hold-down rollers. And, don't forget the dust collection, dust mask, ear protection ... It's a different experience than hand planing.
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  #41  
Old 02-18-2021, 10:28 AM
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warfrat73 warfrat73 is offline
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I think buying a drum sander is off the table.

I've already blown past my "tool budget" buying two planes (in addition to the No. 5 type 16 Stanley Bailey, I also picked up a No. 4 type 9 that needs to be tuned), a razor saw, a couple of decent chisels and a drill press and probably a couple of other small things. And I need to be setting aside money to pay Jayson Bowerman when he finishes my build this summer (I think he'd appreciate that).

But, it did just occur to me to look, and I found out that my university has a fully equipped wood shop for art and design students that has a drum sander.

Problem is, I work for a different unit in the university. I'll shoot off an email later and see if I can get access... though I wouldn't be terribly surprised if they said no. It'd be nice to be able to get it done in just a few minutes without spending any more money.
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"What have I learned but the proper use for several tools" -Gary Snyder

Bourgeois DR-A / Bowerman "Working Man's" OM / Martin Custom D-18 (adi & flame) / Martin OM-21 / Northwood M70 MJ / 1970s Sigma DR-7 / Eastman E6D / Flatiron Signature A5 / Silverangel Econo A
(Call me Dan)
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  #42  
Old 02-18-2021, 10:51 AM
DickHutchings DickHutchings is offline
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Until you master hand planes or can afford a drum sander it's probably best to buy another back, pre-sanded this time just to get going. I have spent a lot of time studying and practicing hand-plane use, sharpening and setup. I love using them, just not for backs and tops. There's no better feeling than just running it through the drum sander, in one side and come out the other all done! I use 60 grit and run at the fastest speed the Intelesense will run. It still gums up a little but I have a roll that I can cut my own from and it's pretty quick to change it out when running rosewoods through it.
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  #43  
Old 02-18-2021, 11:06 AM
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warfrat73 warfrat73 is offline
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Quote:
Originally Posted by DickHutchings View Post
Until you master hand planes or can afford a drum sander it's probably best to buy another back, pre-sanded this time just to get going.
That thought did occur to me, the guy has a couple other sets for sale... about $60 all in... doing that and having it sanded to spec would be easier, and much cheaper than buying a drum sander. But feels a bit like giving up.

I mean, I've already removed about 2/3 of what I need to... on the back anyway. And I've gained a bit of confidence.
__________________
"What have I learned but the proper use for several tools" -Gary Snyder

Bourgeois DR-A / Bowerman "Working Man's" OM / Martin Custom D-18 (adi & flame) / Martin OM-21 / Northwood M70 MJ / 1970s Sigma DR-7 / Eastman E6D / Flatiron Signature A5 / Silverangel Econo A
(Call me Dan)
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  #44  
Old 02-18-2021, 11:30 AM
cobalt60 cobalt60 is offline
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Sorry if you mentioned this already: I'd suggest jointing that back now, so that your thicknessing process also serves to even out any jointing imperfections.

The only downside is that a wide belt sander would need to be twice as wide (basically a 24" instead of a 12" or "industrial not home-hobby size"). Folks like to use planes, but in my opinion, if it's not working perfectly for you, I'd suggest that you can improve your blade skills later, while also moving on with this build by finding a wide belt sander. If you live near a lumber processor, some of them will allow you to pay them for the privilege of running your back through their sander. You might even post to Craigslist or something - I actually allowed a stranger to use my sander based off a CL post once...

Have fun either way!
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  #45  
Old 02-18-2021, 11:50 AM
charles Tauber charles Tauber is offline
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Quote:
Originally Posted by warfrat73 View Post
But, it did just occur to me to look, and I found out that my university has a fully equipped wood shop for art and design students that has a drum sander.

Problem is, I work for a different unit in the university. I'll shoot off an email later and see if I can get access... though I wouldn't be terribly surprised if they said no.
MANY years ago, I commissioned the machinist who ran the machine shop in the Engineering Department of the local university to make me some truss rod nuts and blocks. It cost me very little, and he was happy to do it.

Might be that whomever runs the wood shop at your university might be happy to run the back and sides through the drum sander for a few bucks.

Does it really matter who owns the sander, you or someone else? Having someone else do it isn't a cop-out. It's knowing one's (current) limitations - and preferences - and working around them.

Lots of luthiers farm-out work they either don't want to do or can have done better, faster or cheaper than they can do it themselves. It frees them to do other things, often things they prefer doing.
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