leather double welt?

[Unicorn]

loooong time, no post.  I don't do a lot of upholstery, so I'm a bit kerfuffled by this latest project.  It's a carved oak captain's chair, with a picture frame back and seat.  Owner has supplied a hunk of leather for the job.  He wants piping.  Lots of piping.  I was going to do a double welt, which would probably not be much of a challenge if I was using a fabric, but this is pretty heavy leather.  I did a trial run with it, and it tends to not slide on the machine bed.  It wasn't a very successful trial run.  Am I crazy to even think of doing a double welt?  Is there a trick or two to help me out?  Maybe I should sand the back off the leather to make it more pliable?  Do I need to use a leather needle (I don't have any for my industrial) 

Judy

[SteveA]

There is a tool for thinning out the back of leather called a skiver - round brass nail heads also come to mind instead of piping. 
I guess you could sub out the piping to someone who does leather all the time -
SA

[Unicorn]

I will look into the skiver, thanks!  I'd thought of decorative brass nails, but he wants piping, LOTS OF PIPING!  And BUTTONS!!  I talked him out of the buttons on the seat, and I'll put a few on the back, but even at that I'll have to shave the leather to get it to work in the button press.

[crammage]

Last year I did a set of game chairs in fabric but they wanted a leather double piping.  Fortunately I was able to use some pre-made piping that was in the color they wanted.  It was single welt but I sewed it together to make the double welt and it worked well.  It was also a smaller size than if I would have made it from scratch. 
My problem came to the hot glue, it did not adhere well to the leather.  fussed with it for far too long before it looked good.  Talked with the customer a year later and they are still happy with the results.
Clay

[Darren Henry]

Maybe I should sand the back off the leather to make it more pliable?

Before some one calls me a blow hard, I'd like to mention that I was an orthopaedic shoe maker before I got starved into upholstery, so have worked with a few dead cows.

Skiving actually refers to tapering the edge of a piece of leather from full thickness- to usually nothing before you fold the edge over to get a finished edge.

There are leather splitters that shave the entire width of the strap to a thinner thickness. They do not work on chap/upholstery leather. They are designed for like belt leather etc... and a good one will run you $500 plus.

The three practical options I see are 1) Do as you suggest. I can offer a number of DYI ways to do this, if you'd like.
2) Farm that process out to a shoemaker who has the right tool for the job. It's called a finisher and even a cobbler will have one. 3) Because 1+2 are so labour intensive and prone to wastage (think sneeze and kapoot), have the customer invest in a lighter weight of matching leather. I'd go 2-3 oz in cowhide and I wouldn't sweat the grain. No one would notice on the width of a welt. This is in ascending order of preference BTW. Option 3 being my best recommendation.

Personally; I would much rather use an 18 Gauge stapler etc.. than hot glue * because some leathers have a protective finish on them that will become a problem.

*Staple on the stitch line and the staples will pull the two welts together to hide the staples most of the time. The rest you have to manipulate the welts manually.

[Unicorn]

I did the buttons, for the most part they turned out not too badly.  I spent a good part of the afternoon scraping the suede off the backside with a razor until it was thin enough to fit into the button press.  Some were still a bit too thick and the press cut the leather around part of the edge, but I think I have 5 or 6 usable buttons, which is all I need for the seat back.  What I've read about welting is to use the hot glue, "never a staple gun".  I agree though that a staple gun will pull the two edges together far better than using glue, especially if I use a narrow crown - but I'll try a sample first.  I so don't want to screw up this chair.  His wife tells me he spent MANY HOURS refinishing it.   I could tell by the glint in his eyes when he showed me the chair and the leather that he was beyond pleased with himself (he really did do a nice job). Still debating how to do the seat.  It's picture frame the same as the back - I can either cut a 1/4" board to fit in and finish that and drop it in, or I can use webbing.  I think he'll get better support with the plywood (with channels cut for some flexibility)

Some other DIY methods for thinning out the leather would be very much appreciated.  With three frames to double welt, I'll be scraping for a very long time, although I don't think I have to go quite as skinny as I did for the buttons.

[wizzard]

faced this issue of double welt a couple of times.
I cut the leather in the same width than fabric. Before sewing I steam with my iron (doefix steam iron) the leather on the back side.
That way it becomes very soft. You can easy stretch it or work it in this condition.
One negative - If you are a slow worker it will cool out and you would have to start again.
I also don't use the standard double welt as it will come out way to big. Make the double welt from scratch with a smaller welt.
You do have to cut the excess leather carefully. I always worked like a charm for me. Issue is more of using the correct glue adhesive, so the double welt does not fall off.

[wizzard]

I spent a good part of the afternoon scraping the suede off the backside with a razor until it was thin enough to fit into the button press

Faced this issues already many times and solved it in using a grinding wheel to take some of the back off the leather.

I know it is unconventional, but faster than working with a razor blade.
Using the grinding wheel on a slow speed setting, it will take off most of the back of the leather in no time;  Time is Money!

Just watch your fingers, you do this on your own risk!
Some practice is necessary. But my buttons came out perfectly and the leather piece fitted into the button machine with no issues. 

[Unicorn]

never thought of the grinding wheel!  What a great idea!  Will give it a go on a small section to see how I do.

[wizzard]

let me know how it worked for you.
As I said just watch your fingers. It is a solution which only works for the buttons, as one has to work only with a small piece.
Larger pieces should be done with a skiver, but I don't see the justification to spend $1,200.-- on such a machine just to make buttons.
Not that I'm el cheopo, but I do have to see a return of investment. Buttons are just not made on a daily basis.

[Darren Henry]

A grinding wheel does work in a pinch,but the right type sander works best. Oscillating or palm sanders don't work well. You need the sand paper moving in only direction, and you draw the leather against that movement---not with it.

My first choice would be a belt sander. Staple * the piece of leather to a SMOOTH CLEAN surface and use very light pressure as you draw the belt sander towards you at right angles to stretch of the leather.i.e run the length of the cow,not the width. I'd start out with an old worn belt until you get comfortable with the feel for it. I'd also start out with strips no wider than the sander, that way you are only focused on one direction.

*If you tip your stapler to one side one "shoulder" of the staple will stand proud of the wood and be easy to get ahold of to remove.

For any other sanding device, like my portable finisher here;



you draw the leather past the stationary sanding surface. With thin leather like this you need to support it on a smooth surface as you pass it over the belt/drum,whatever. You want just a little flex in this "table". A piece of wood paneling works alright...A piece of sole leather works best if you have one.

either way use light pressure, medium speed, and long smooth passes. Don't go for the home run---expect to make several passes until you get to the thickness you want. And yes---watch your knuckles, especially with option B.

[Unicorn]

I tried the grinding wheel last night on a scrap.  That was pretty slick and will work great for buttons (in the future).  I'll cut a sample strip for the welt and try the belt sander.  I can slow that speed down, my good grinder isn't variable speed. Once I'm happy with the welt, I'll be able to move forward with the chair.  Thanks for the great advice!

[wizzard]

I'll cut a sample strip for the welt and try the belt sander.

I have never tried to sand the leather for the welting,
As I have a steam iron, I just steamed the leather on the reverse and the made the welting.
When the leather is warm, one can easily work with it. After cooling down, it really is a nice tight fit around the welt.
At present I work on a Fritz Hansen Chair on a re-upholstery job. Use the double welt on the edge to cover up the staples.
But in this case I just soak the leather, sew it in wet condition and apply it around the chair. As the Leather tries it shrinks and is a tight fit on the edges.

[Darren Henry]

---the belt sander.  I can slow that speed down

I wouldn't. At least not too much. My finisher is the same as this old fossil.



it turns about the speed of #2 on your belt sander

The newer style finishers with the belts instead of drums run at like 5 or max on your belt sander.


It sounds illogical; but they are actually easier to control than the old slow pokes. My guess is that it is because they rip the flesh side off before it has a chance to "stick" to the sand paper. IMHO keep the speed up---and increase the grit  of the paper. I have worked with both styles of finishers over the years and it is easier to use 100 grit on a new machine than it is to use 40 grit on my old clunker to get the same result in the same time. My 1.67 US cents.

[Unicorn]

Could have sworn my little belt sander was variable, but it isn't.  It's a small stationary upright sander. It did work quite well on the scrap I tried, but I will have to be very careful not to twist the band of leather.  I'm only trying to remove some of the suede off the backside, so once I've cut my strips, and exercise patience I should be fine. May also use the smaller of the two welt cords, it provides a slightly less bulky look.