messenger bag Looking for advice for messenger bag project

[EfrainBG]

   Hi, everybody!

   I'm about to embark in my second large project. I don't know whether that's the right term, but it's how I saw it referred to in a Youtube tutorial (by Leodis Leather). It basically refers to a bag with the stitches on the inside... saddle stitching, that is.

   I'm planning to make  a bag somewhat similar to a Brixton by Ona Bags: esentially, a messenger bag with two pockets on the front side and one pocket on each side of the bag. Although I won't be selling this bag since it's for myself, I plan to make some modifications to the design as to keep it original, such as measures, form, handles, straps, thickness of leather to be used, no lining, fastening with double rings instead of buckles, burnished instead of folded over edges, attachment points in the corners to extra stuff (tripods, blankets, whatnot...), etc. In the end, it would be a bag of about 15"W x 12"H x 5-6"D

   As I said before, the bag won't be lined, since I intend to use a heavy full grain leather. In the range of heavy leathers, I currently have access only to a 8-10 oz that seems to be chrome tanned (when you cut it it has a white/blueish color in the middle) with some color applied to both sides of the leather. I know it's a thick leather for a bag and I have some questions about it.

   First of all, the leather used in Ona seems to be about 3-4 oz (only a guess from what I see in the photos and some basic scale math I've been doing). Actually, I intend to make my bag from a leather in the 5-6 oz range, either by searching for a different leather source or by thinning down on what I have at hand. and here is where my first question lies: how do I thin down from 8-10 to 5-6 oz without a splitter? I would need to thin down the entire piece of leather before cutting to achieve a uniform look and feel for the bag. I thought of using a circular sander on the suede-like side, but I've made some tests and it would be an obscene amount of work to do. On the other hand, I've noticed that sanding really ends up softenning the leather up really nice, no matter how thick it ends up being.

   My second question:

   If you look at the picture, you'll see that on the corners of the fron side of the bag, there would be as many as four layers of leather to be sewn together. If I manage to reduce the thickness of the leather to my target 5-6 oz, we're still talking of a seam that would around 8-10 mm thick... and that's only on a straight line. Wouldn't this put too much stress on the joints when I try to flip the bag inside out? how about the corners? By the way, I'm using (or planning to use) Tandy's Tejas poly waxed thread... it fades a bit with extensive use, but that's actually something I've come to like in my backpack and a couple wallets I've made so far.

   If the stress is too much on the joints, what are my choices? skive the places where the seams will be? or change the design altogether to an outside stitch one?

   One possibility I've been contemplating (although I would really like to make it this way) is to get rid of the side pockets and instead put some attachment straps to do some sort of modular system. This would add the benefit of loosing some wanted weight depending on the situation.

   I hope I made any sense and I'm really looking for your advice on this one.

[bikermutt07]

I am absolutely no expert. I have working on a tote with some really thin leather that I doubled. It was probably 2/3 ounce and now it's too thick. I think the best thing for you is to back up and get a thinner leather. Save that thick stuff for something else. I imagine it will make assembly a nightmare, not to mention finishing it only to find it's too heavy to lug around.

.02

Edited June 3, 2016 by bikermutt07

[EfrainBG]

13 hours ago, bikermutt07 said:

I am absolutely no expert. I have working on a tote with some really thin leather that I doubled. It was probably 2/3 ounce and now it's too thick. I think the best thing for you is to back up and get a thinner leather. Save that thick stuff for something else. I imagine it will make assembly a nightmare, not to mention finishing it only to find it's too heavy to lug around.

.02

thanks a lot, man.

now, newbie here too, so... when you say "doubled", does that mean you glued/sewn two layers together?

I totally see your point, don't get me wrong. I have actually considered using thinner leather, but at 5-6 we're talking about 2 mm thick. At anything less than that, my guess is that I'd be forced to use lining to let the bag hold some structure. I don't like the idea of lining, but I could give it a go... a new thing to learn never hurts. Gear protection is not that critical since I'd be using a padded insert.

Again, I've never worked with leather this thin before, so, I'm open to suggestions. I just wanted to be sure that 4-5 or 5-6 oz was not too ambitious.

Thank you!

[bikermutt07]

I think and I stress think 4/5 should be just right. The leather I'm using was bought a few years ago on sale at tandy. I didn't remember what thickness it was but it felt pretty stretchy. So, I used contact cement and glued two layers together for the body and straps. I don't have a gauge but it's about a 1/4 inch thick now. I would guess it's 5/6 ounce now. I haven't started sewing it yet but I'll bet a million dollars it's going to be a booger to turn right side out when I finish. This is my first bag and I'm trying out all kinds of stuff that's new to me. Luckily, my wife is an art teacher and doesn't mind me experimenting on her new tote.

I may be wrong about the current weight now after reading your post again. But I'm pretty confident anything more than an 1/8 inch thick would probably be overkill.

[EfrainBG]

8 hours ago, bikermutt07 said:

I think and I stress think 4/5 should be just right. The leather I'm using was bought a few years ago on sale at tandy. I didn't remember what thickness it was but it felt pretty stretchy. So, I used contact cement and glued two layers together for the body and straps. I don't have a gauge but it's about a 1/4 inch thick now. I would guess it's 5/6 ounce now. I haven't started sewing it yet but I'll bet a million dollars it's going to be a booger to turn right side out when I finish. This is my first bag and I'm trying out all kinds of stuff that's new to me. Luckily, my wife is an art teacher and doesn't mind me experimenting on her new tote.

I may be wrong about the current weight now after reading your post again. But I'm pretty confident anything more than an 1/8 inch thick would probably be overkill.

   well... as per Tandy's guide, 1 oz = 1/64 of an inch... so, I'm aiming for 1/16-3/32 tops!!

   I made a backpack with the same leather but at full thickness and it ended up being about 1/8 thick (1/4 in the seams and even more in reinforced areas). It's a tank!!! (about 8 pounds empty) but it was all sewn so the stitches are visible. It was definitely a struggle in some places but it was worth it (for a backpack).

   here's a link to a show-off post: 

 

[bikermutt07]

So, I saw your backpack. Yeah, you don't need any help from me. That thing is gorgeous.

[EfrainBG]

17 hours ago, bikermutt07 said:

So, I saw your backpack. Yeah, you don't need any help from me. That thing is gorgeous.

  oh, don't say that, man!! It's full of errors!! (most of them very well hidden:)

 this is a totally new kind of beast I'm tackling and I need all the help I can get.

[bikermutt07]

Well it looks great.