The Upholstery Forum

Having trouble getting my seats to fit just right.

Do you guys normally factor in a seam allowance when tracing the foam out? I've heard mixed options on this...

When I did mine I used the old material as a pattern and added 1/2' from where the original seams were. The one time I didn't was one the 3 bottom cushions in the bow. I used the wood as a pattern and added a 1/2". Not realizing the old foam had a slight slope inwards towards the top which left me with an empty void at the seam.

I remedied that by buying new foam (kinda needed it anyways to be honest) and cut the new foam with straight side slightly larger then the wood backer for a snug fit.

If I were to use the foam as a pattern, I think I would add 1/8" to 1/4" to the size for the fabric but stitch it at 1/2" so it would make a nice tight fit.

Now, bear in mind I have not done this yet and only have my one boat under my belt but that is how I would tackle it.

Depends, if it's got a wood back or a box cushion. On a box cushion, i add 1/4 seam allowance then sew at 3/8. With a wood back, use the wood as a template and add 3/8 and sew at 3/8. If i plan on top stitching then i goto a half inch allowance.

Typically you want to have a 1/2" more foam all the way around to put the cover under tension, but if the foam is really dense then you may only be able to have a 1/4" more foam than the cover.

So people usually cut the upholster the same ans the foam and then sew at 1/2" seam allowance to get the 1/2" of compression on the foam from the cover.