Hello from North Wales

[AndrewWR]

My name is Andrew W-R and I'm new to working with leather. That said, I've often quoted architect, Daniel Burnham: "Make no little plans". With those wise words in mind, I came to leatherworking because I wanted a bag that just wasn't available. So I made it myself.

I made mistakes along the way but I got there in the end. (These pictures are of a work in progress: I hadn't considered my edge finishing options.)

I joined your on-line community because I wanted to share a pencil case design I was quite pleased with. The feedback on it has been positive and I'm looking forward to seeing what other leatherworkers make of the design.

My new project involves finding a way to directly bond carbon fibre to leather. I'm planning to make a traditional looking leather suitcase with a composite shell inside. I'll let you know how it works out.

Andrew W-R

[cjartist]

Welcome to our happy place! Nice looking bag.

[cjmt]

5 hours ago, AndrewWR said:

 

My new project involves finding a way to directly bond carbon fibre to leather. I'm planning to make a traditional looking leather suitcase with a composite shell inside. I'll let you know how it works out.

Andrew W-R

Interesting idea! If the idea is a rigid structure I imagine whatever bonds the layers of carbon fibre will also work on the  leather outer

Charlie

[DJole]

Beautiful North Wales! I enjoyed a bank holiday weekend up in your part of the world back when I was studying Welsh for a summer at Lampeter.
I have a treasured t-shirt from Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch-- I call it my thousand dollar shirt!
But enough about Wales -- that's a nice first effort bag! (But it's hard to see the details since it's photographed on that darn brown table in what appears to be ambient lighting)
I made a bag for the same reason you did. I need to rework my handle, though... someday I'll get around to it. 

[AndrewWR]

15 hours ago, DJole said:

Beautiful North Wales! I enjoyed a bank holiday weekend up in your part of the world back when I was studying Welsh for a summer at Lampeter.
I have a treasured t-shirt from Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch-- I call it my thousand dollar shirt!
But enough about Wales -- that's a nice first effort bag! (But it's hard to see the details since it's photographed on that darn brown table in what appears to be ambient lighting)
I made a bag for the same reason you did. I need to rework my handle, though... someday I'll get around to it. 

I'm curious: Why $1000?

I actually live within walking distance of Llanfair P.G. (we only use the full name to promote tourism).

Sorry the photos were dark. They were taken with a phone and I only include them to illustrate the point of quoting Daniel Burnham. Also, that wasn't just my first attempt at a bag. It was my first attempt at anything in leather. The features that make the bag special (What I couldn't get in a shop) are two separate, NFC shielded laptop compartments and an integrated rigid carbon composite back board that the D rings are actually attached to, which takes all the stress under load. That rigidity also allows it to serve as a lap desk. I find that my actual lap is too low for comfortable use of a laptop. A table is usually about 5" above my lap. This bag raises the computer 5", provides solid surface to work on, allows better ventilation to the computer and doesn't slowly cook my thighs.

You should be able to see where the carbon sheet extends to within a few millimetres of the stitching (its a 2mm thick A3 panel).

 

[AndrewWR]

On ‎11‎/‎03‎/‎2017 at 4:25 PM, cjmt said:

Interesting idea! If the idea is a rigid structure I imagine whatever bonds the layers of carbon fibre will also work on the  leather outer

Charlie

Whatever bonds the layers of carbon is epoxy resin. The issues with bonding it onto leather only start with the epoxy. 

Wax and oils in leather make it the exact opposite of the "clean, dry, grease-free surface" adhesives generally require. I'm experimenting with a variety of solvents (including Toluene, Acetone, Isopropyl Alcohol and Methyl-ethyl-ketone) to deglaze the back of bridle leather enough to get good adhesion without detriment to the hide. I don't want it delaminating around stress points such as strap attachments.

There is also the issue that I will have to use a cold curing epoxy and wet-lay the carbon sheet because the leather won't withstand an autoclave.

There is no feasible way to vacuum bag the carbon: One of the most common techniques for applying pressure to the material during the curing process. I'm currently considering holding the leather bag within a rigid box while applying pressure to the composite by inflating bladder made of vacuum bagging material inside my project.

A decent surface finish for the composite can probably only be achieved by masking up all the leather and applying gelcoat with a spray gun.

Edge finishing is an issue. Always a consideration with leather but I'll also have to deal with the cut edges of carbon fabric. Currently, I'm expecting to pre-punch the leather for stitching a rolled over edge, then pass a 1.5mm drill through each stitching hole after applying and curing the carbon in order to stitch right through the hard shell.

Finally, there  is the issue of sealing any seams prior to applying epoxy, which has lower viscosity than water, to avoid leakage through to the outside of the bag which would ruin the surface finish of the leather outer.

Bridle butts aren't cheap but the carbon fabric is even more expensive so I have to be very sure I've worked out all the technical issues first.

Proper Prior Planning Prevents Piss-Poor Performance.

 

 

 

[cjmt]

I think it's unlikely you'll successfully de wax the bridle. Why not just slit the back off though? It won't be waxy all the way through. Split 4mm bridle to 3mm and you'll have a good glueing surface ready to go

[DJole]

On 3/12/2017 at 9:51 AM, AndrewWR said:

I'm curious: Why $1000?

I actually live within walking distance of Llanfair P.G. (we only use the full name to promote tourism).

Sorry the photos were dark. They were taken with a phone and I only include them to illustrate the point of quoting Daniel Burnham. Also, that wasn't just my first attempt at a bag. It was my first attempt at anything in leather. The features that make the bag special (What I couldn't get in a shop) are two separate, NFC shielded laptop compartments and an integrated rigid carbon composite back board that the D rings are actually attached to, which takes all the stress under load. That rigidity also allows it to serve as a lap desk. I find that my actual lap is too low for comfortable use of a laptop. A table is usually about 5" above my lap. This bag raises the computer 5", provides solid surface to work on, allows better ventilation to the computer and doesn't slowly cook my thighs.You should be able to see where the carbon sheet extends to within a few millimetres of the stitching (its a 2mm thick A3 panel).

 

It's a joke-- the thousand dollars was the price of the Welsh course, which was the reason I went to Wales (not just to get a tshirt!).

I actually hiked from Bangor to Llanfair P. G., and then I continued on to Bryn Celli Ddu. That was quite a bit of a walk, I must say! I did get a ride back to town from a friendly surfing lad who'd been over near Aberffraw, and that was very helpful.

The ability to make custom bags is one of the things that attracts me to leather work -- you can put in the features and design elements that you want. I love your design concept for a lap-top desk/ computer case. (I can't just call it a bag, since it's so much more than that!)

[AndrewWR]

Bag Number 2. Specifically styled to match my first bag. This weekender or holdall is 10"x10"x20", suede lined, has a 2mm carbon fibre base board and replaceable rubber feet.

All the fittings are marine grade stainless steel ('cept the Loxx fasteners, which are chromed brass but sold for marine use).

The decision to not have a shoulder strap is deliberate. I've never liked using them.