Stitching Groovers weaken seam?

[K-Man]

Anyone ever heard by using this tool that you're creating a weak point on the leather/item? Apparently there's a holster maker who claims that by using the stitch groover, you're creating that. I could see if you had a piece of leather that was 2-3 ounce in weight, and by using this tool on it, you're going to gouge into a good portion of the thickness. But if you're using a piece of leather that's thicker than that, I have a hard time believing the use of the stitch groover is going to create a weak point, at least enough to be concerned about.

[Don101]

ive been using a stitching groover since day one and made hundreds of holsters and never heard that its a week point or that any of my holsters have come apart, it helps protect the stitch against wear and also gives it a better look on the finished item.

[abn]

Apparently, your holster-making friend isn't the only one who thinks this way. Here's a post in which Bob Beard (via ClayB) brings up the same point:

This reminded me of something Bob Beard brought up in a class making a checkbook cover. Bob said that he doesn't gouge a stitch groove when he sews. Why? Because if the grain side is where all the strength is, and you gouge that away, didn't you just remove the strength of the leather? Bob said that he will use a modeling tool to press in a stitch line without cutting into or removing the grain side. Goes against most instructions on sewing leather, but it does bring up a valid point.

(Original thread)

I don't subscribe to this school of thought, and much prefer to see stitches indented using a stitching groover.

-Alex

[K-Man]

Not disputing Bob Beard's theory - but if you follow that line of thought, aren't you creating a weak point in the leather then when you use a swivel knife to cut the lines for tooling?

[CitizenKate]

Anything that breaks the grain side of the leather, will weaken it, so I agree with those who advise against using a groover. On one piece I was sewing, which I had made a cut groove on, I was actually able to tear the leather with my bare hands along the line that had been grooved. Imagine how much easier once the holes are punched. Since then I have not used a cut groove to mark a seam line.

This should also be considered when carving a design into any piece (as in, with a swivel knife) that will bear a load (such as a dog leash), unless the leather used is fairly heavy.

Kate

Edited June 11, 2007 by CitizenKate

[D.A. Kabatoff]

I think that the item being made and the weight of the leather needs to be taken into consideration when making the decision to groove or not groove. As a saddlemaker, I would'nt even consider the idea of not using a stitch groover because most areas of the saddle receive alot of rubbing over the years and it is important to protect the stitching in this manner. Simply creasing the leather will not achieve this as effectively.

In some areas such as flat plate rigging,which receives alot of stress, I groove the same line twice on the upper stitching. This is so after it is sewn, the threads are deep enough that the edge of the groove can be pushed over the stitching, almost completely covering the stitching from the constant motion of fenders and stirrup leathers rubbing back and forth. On a saddle I have never seen a problem that can be solely blamed on a stitch groove. I can't speak so much for lighter leathers, but on heavy leathers there doesn't seem to be any reason not to groove.

Darc

[K-Man]

Kate:

What ounce weight and type of leather were you using in the instance where you could tear it after using the groover?

[abn]

I think that the item being made and the weight of the leather needs to be taken into consideration when making the decision to groove or not groove. As a saddlemaker, I would'nt even consider the idea of not using a stitch groover because most areas of the saddle receive alot of rubbing over the years and it is important to protect the stitching in this manner. Simply creasing the leather will not achieve this as effectively.

In some areas such as flat plate rigging,which receives alot of stress, I groove the same line twice on the upper stitching. This is so after it is sewn, the threads are deep enough that the edge of the groove can be pushed over the stitching, almost completely covering the stitching from the constant motion of fenders and stirrup leathers rubbing back and forth. On a saddle I have never seen a problem that can be solely blamed on a stitch groove. I can't speak so much for lighter leathers, but on heavy leathers there doesn't seem to be any reason not to groove.

Darc

Very well put, Darc. Thanks for sharing your thoughts on the subject.

-Alex

[Art]

It always occured to me that way. I use a screw creaser to put a groove in the grain the sew in the grove. That being said, I haven't seen many seams fail either way.

Art

Anyone ever heard by using this tool that you're creating a weak point on the leather/item? Apparently there's a holster maker who claims that by using the stitch groover, you're creating that. I could see if you had a piece of leather that was 2-3 ounce in weight, and by using this tool on it, you're going to gouge into a good portion of the thickness. But if you're using a piece of leather that's thicker than that, I have a hard time believing the use of the stitch groover is going to create a weak point, at least enough to be concerned about.

[bruce johnson]

To follow Darcy's example, I do the same on flat plates and skirts. There is no tension across these lines, they are holding either a lining layer or plug and shearling on. The abrasion on these threads is what hurts them.

To carry this one step further. I saw a saddle in a booth at the NFR - nice handmade setup. I kept thinking something looked odd, but couldn't place it. You know how when something is NOT there, you know it, but don't know what it is. Hit me. There was no stitching on the skirts or plate. What this old guy does is to stitch in a swivel knife cut. Then glued it and pounded it closed. His theory was more protection from abrasion, and the grit getting down into the stitch holes and abrading the stitches. Anybody else doing this??

Bruce