Official Luthiers Forum!

Following on from my earlier post I managed to split a spruce billet, can't say that it really worked out as planned. However I can't seem to find a decent piece that has the grain running end to end.

See pics, is this run out?

I cut some 18" * 3/4" X braces and marked where the grain ends with a pencil. Is this unsuitable for x braces ?

Hard for me to tell from these pictures just what you are showing us.

If the top picture shows the flat 3/4" face, are you showing us the top edge just under [in the first picture ?

Run out can be an issue in either direction but my main concern for your wood is the quarter sawed edge. That is where you should see as may as possible grain lines run from end to end.

Was your spruce board quarter sawed on the wide face ?

These pictures seen too focused in on a small area - try posting picture of the whole board - include the end so we can see the grain.

Steve

_________________
Building for the love of building.

The patterns on the sides of the braces you're showing is run-out, but it doesn't look terrible. However, I would look at the "top and bottom" of the braces to see how the grain lines run end-to-end rather than the sides, as you've shown. I wouldn't want to make any judgement on those pieces until I'd seen photos of the top and bottom of each piece, and the end to see how well quartered they are. Just my opinion.

Top & bottom... AND the end grain. From what I have seen so far, I would not choose these pieces for X braces or the upper transverse brace.

Some more pictures

See teh pencil line which is about 20mm, that is where I woudl run off a length for a brace, I can't avoid having run-out

John

I am probably less fussy about braces than I should be. I look at the end grain and make sure they are neatly quarter sawn. If one end is off quarter by a little I still use them. Once you get them to size, (my x-braces are ¼ x 9/16), I flex them and look for weakness and stiffness (once in a while they will even snap)

When you look at the sides of my braces you generally see some run out, pretty much as your’s do.

_________________
Joe Beaver
Maker of Sawdust

I see your pics now. What kind of wood is that? Looks like pine or fir. What are you going to brace?

_________________
Joe Beaver
Maker of Sawdust

According to the invoice spruce

Picture before it was split attached

There is a common misconception that run-out can be seen by planing the side of the quartersawn billet and seeing if the grain rises or falls. Incorrect!!! This only tells you whether the grain is moving in or out of the "x" plane. You want to know whether the grain is rising or falling in the "z" plane. For reference, I am describing x as the width, y as the height, and z as the thickness. The only way to know the run-out is to start with split billets. If you have enough material, then split it yourself at the end and with your chisel face across the quartersawn growth lines. Hope that helps.

I use sitka or sometimes red spruce. I'm use to a lot more growth rings per inch. I'm not familiar with what you have there. It might be a locally used wood with good success. I just don't know.

I'm sure one of the 'wood guys' will be along and be able to help out.

_________________
Joe Beaver
Maker of Sawdust

The dark sections on the side of the wood are places where the vertical grain intersects the plane of the side of the brace.
it could indicate runout as seen in the pictures others have posted, or in very tight grained pices of spruce, there is always some of that, usually blotchy, or lines, but it does not indicate the direction of the long grain runout, which is invisible once the brace is sanded, and is best seen by splitting.

In my pictures, one brace has "invisible" runout, where you can see the grain is running at an angle to the length of the brace, and actually runs out the top and bottom of the brace! You can't see it from the top or bottom once sanded either. This was a commercial brace I purchased from a supplier, and a reputable one at that. I have actually seen braces that have failed along those grain lines, and these types of braces are less stiff.

The other brace is one I prepared myself by personally splitting from brace stock. It has a wave on one side which I cut off the rest of the braces from that batch so I only used the straight portion, but you can see the split runs the entire length of the brace, with no invisible runout. It also has no blotches, because the grain is perfectly vertical with no intersection as the side plane happens to fall between the dark grain lines.

_________________
Old growth, shmold growth!

Chris Paulick covers this topic pretty well.

You can't see runout with the naked eye unless you split the wood (or looking at the finished bookmatched top halves).

Look at this sample:



What you see in the picture above is NOT runout, but just the grain lines,

and here you see some faint tool marks:


This is the actual runout of that sample:


Still the same sample, but the left part 1b) is smoothed again with a knife. In 1b) the nice runout got invisible again:


Looking at 1b) with a magnifying glass, loupe or cheap "microscope"...


...you can see the runout again:


I hope that helps.

All the pictures in this post show the same wood sample, also the microscopic picture.
Again: there is no way to see runout with the naked eye on a not-broken surface.

Here you can find some more text and pictures about how to detect runout.

Great pics Markus!

_________________
Old growth, shmold growth!

Chris's video explains run out very well,however I am sure that when Chris splits the billet he splits it at 90 degrees to the line of the grain, in other words across the grain not with the grain whereas when Cumpiano describes splitting a billet he mentions splitting it parallel to the grain. Which is correct or have I misunderstood ?


Also in a 3*2 billet would there be mode than one instance of run out or is the assumption you hit in once down the middle and that locates the only run out ?

John

Actually both. You split parallel to the grain to define the vertical endgrain, which is visible, and you split 90 degrees to the vertical endgrain and along the longrain, to ensure no runout and to check for twist, although you can see twist if one end of the brace has vertical endgrain and the other end goes off vertical.

When you split the brace stock you want to split slowly. You also need a splitting tool that wedges the wood apart evenly, VS a chisel, which wedges one side further than the other and cause it to break across the grain VS splitting along the grain. At leas in my experience......

_________________
Old growth, shmold growth!

Here's how I prepared the brace I previously posted with no runout in any of the planes.

Split along the side grain, split perpendicular to the vertical grain, saw along the true planes, sand in the sander.

In order to get true faces the brace stock must also be true. Sadly, the (brace) billets most vendors sell are offcuts, with twist and cracks, and I find them to be unusable for braces. I actually purchased soundboard billets to split my braces from, as I believe the brace stock is as important as the soundboard itself, and is worth the extra time and expense to make it correct.

Interestingly, in the side grain shot, as it was split, you can see the invisible grain direction. That goes away when sanded and you can't see it with the naked eye anymore.

_________________
Old growth, shmold growth!

BTW Cumpiano STARTS with a brace billet that has been split perpendicular to the endgrain already, as I believe is stated in his book. I haven't read it in a while, but when I took his tutorial that is how he explained it to me. That's why in the text he describes splitting parallel to the grain for the remaining steps.

_________________
Old growth, shmold growth!

So I should have split this perpendicular to the grain first?

Is there only likely one instance of run out in each sample 3"*3" square ?

J

Well, it depends on what you are starting with. Is the grain straight or wavy? Is the board twisted?

It's hard to tell unless you've processed the raw lumber yourself from the start, or know how the person you bought from processed it.

So in a 3X3 billet, if it was sawn from a plank and run through a planer, the grain could be running any direction, the length could have a twist, and you wouldn't know until you started splitting it.

If you start with a 4X8X22 soundboard billet processed from a split wedge, with straight even grain and no visible twist, you will likely be able to split the braces with no runout and be very efficient.

_________________
Old growth, shmold growth!

It was about 3*3*22 before splitting - from both ends the grain looked the same but from what I can gather that is no indication that there is no run-out

J

So in that case you wouldn't know how many instances of runout there would be until you start splitting.

_________________
Old growth, shmold growth!

Splitting very small stock can be problematic, because with little wood on either side of the split, the billet may or may not split correctly, with or without runout.

When you buy a "prepared" brace stock blank that's only 3x3 or smaller, slice-off a full-length piece a little less than 1/4" thick on the table saw or bandsaw with a fresh blade. This will be a sacrificial piece, as you'll see in a second..!

Now, grab this piece at each end, and slowly twist each end in opposite directions, until it breaks. If it has minimal runout, it will break(split) reasonably straight along the length, and though it may not break/split down the center, what you want to see is a nearly parallel break/split. This will clearly show if you have any lengthwise runout. Now you can sight down the length of the break, and check for side to side runout by noting if the break is parallel, or close to parallel, to the upper and lower surfaces, and if it has any twist.

If this sacrificial piece checked out decently, just go ahead and saw the rest of the braces off that same face, and you can be pretty certain you'll have excellent braces.

BTW, I didn't read the whole thread here, but if it hasn't been mentioned yet, the two keys to splitting are a dull tool(I use a small "camping" axe that is duller than a butter knife) and to ---always--- split down the middle, no matter direction you're splitting. You want equal resistance to splitting on either side of the split, otherwise, the split will take the easy way out and you won't get a true "read" on the grain. It's a bit of an art form, really, and it's worthwhile to find some 2x4 scraps(stop-by any construction site! They'll love you for hauling-off their off-cuts!) or even buying a 2x4 or two, cutting them to 24" lengths, and practice splitting these, while studying the wood, and especially the wood's grain, on all 3 axis.