Estimating Upholstery Material

[NHGuy]

So next project is to recover the interior of my boat.
I already had a sewing machine. I have watched some videos, bought some heavy duty thread and some #16 needles. I brought home a few swatches of vinyl, the machine sews it fine.
I removed my boat interior and brought it in the basement to work on over the winter. I unstapled a lot of the complex looking stuff so I could replicate what was done before. And I measured off all the parts.

So here's the question. Do I calculate my material in square inches and add a fudge factor?
I'm looking to get 54" wide naugahyde/vinyl. Do I use 54" X 36" = 1944 square inches per linear yard? Do I just take my required square inches of material and divide by that 1944 to get the needed yards of vinyl? My thinking is that's the way, but this is all new to me so I'm looking to make sure not to do something wrong or purchase the wrong amount.

I'll replace and coat the wood backing and remount it using T nuts as it was before. And I will plastic bag the foam. I'm not really changing anything just renewing it.

 

[Woodonglass]

Re: Estimating Upholstery Material

I'd measure and calculate sq. ft. A yard of vinyl is about 13 sq. ft. IMHO you need #18 or 20 needles and Marine Bonded Thread if you want it to last. This place has everything you need and Good Prices too!!
Upholstery Fabric, Wholesale and Discount Auto, Marine, and Furniture Upholstery Fabrics

Unstitch the existing covers and use them as your patterns. All pieces should have approx. 5/8" allowance. Do the existing covers have piping? Are you wanting piping. If so, you'll need a zipper foot or you can buy special Piping Feet for your machine. What Make and model of machine did you get?

 

[jbillingsley]

Re: Estimating Upholstery Material

I get 1296 square inches per square yard. Calculating as 12"x12"x3'x3'. Works out the same as 36"x36", so I think I have my math right. 54"x 36" is 1944 square inches, as you calculated. 1944 square inches is 1.5 square yards. I'm not sure if vinyl is like carpet, but I would buy extra just to be sure it all looks the same vs. a later purchase having a slightly different tint to it.

 

[JDA1975]

Re: Estimating Upholstery Material

I calculate by square inch, then add 20% for waste, a lot of odd cuts will leave unusable scraps....of course another factor is welt length, if I figure I need 4 yards, but my longest welt is 15', I will buy 5 yards just so I have a clean welt, you can splice welts, but every splice sticks out. Wood is correct on needle size, minimum 18 with v92 poly sunguard thread, most non commercial machines will not take needles over 18, but I would not go with a 16 you will have a lot of headaches with cut thread.


on vinyl you dont really figure suare yardage, since material is 54" wide, he just misspoke, and meant lineal yard 54"X36"

 

[Woodonglass]

Re: Estimating Upholstery Material

Here's an example. If your seat it 18" wide and 20" tall on the back and the seat portion is 18" x 18" and they are both 4 inches thick I'd calculate it as approx. 12 square ft ( 2 ft by 3 ft times 2) and 1 Yard of vinyl (13.5 sq. ft) would cover the seat NOT counting Welting.

 

[fishrdan]

Re: Estimating Upholstery Material

Draw it up on paper so you know how much material you'll need. (I always buy 10-20% extra just to make sure I have enough.) If the vinyl has any grain to it at all, make sure all the parts have the grain going the same direction. This will most likely use more vinyl, but will make a better looking final product. If you cut a section with the grain going the wrong direction to save material, it will be noticeable.