A QUESTION ABOUT SEAMS?

Hi Gareth

Are you sewing it inside out? If there is a lot of excess then trim it a little, but particularly trim the corner quite close to the stitching. That makes for a neater, pointier corner once you turn it the right way out. Make sense?

I'm not sure about double stitching, I'll let someone else answer. I would think a second row would do nothing as all the force is on the first row?

Look at http://thru-hiker.com/projects/basic_seams.php

Good description of basic seams

also if you go up a level and then go to French Seams, that's another useful one

Oddly enough, I was just thinking about this same project this morning, because my brother recently got me back into climbing and bouldering.

I think for your purposes a french seam, or something of the sorts, would be most useful. It should give your seams a good deal extra strength.

What are you going to use for the actual padding?

Look up "top stitch". That will spread the force over two rows of stitching. If the raw
edge is inside the pad, you won't need a lap felled seam.

Look up notching the corners too.

FYI, and to answer a question above:

Lots of the pad manufacturers sell replacement foam. I've never had to buy any, but know people who have. Some quick links, but I'm sure any company would sell you some:

http://www.asanaclimbing.com/foamReplace.htm
http://www.organicclimbing.com/
http://www.mistymountain.com/c/recreational.htm

a little weigh-in from another climber making his own gear:

i would go with a double line of stitching in a simple seam arrangement. French seams are for concealing the raw edges either 1) for aesthetic reasons (those frenchies and their style…) or 2) to prevent raveling, i.e., fraying of the edges where the individual threads of the fabric start to separate. In your case the seam is inside where it won't be seen, and you can prevent raveling by lightly searing your fabric edges with a candle.

likewise i think topstitching is unnecessary. in your case there is not a lot of tension perpendicular to your seam so you don't really need to distribute it across multiple rows of stitching.

personally i would use two lines of stitching separated by 1/8" or less. this way if the first row, which is indeed taking all of the stress on the seam, fails, there is a backup seam and you won't even notice the failure.