Thursday, May 31, 2018

How to Make Round Poster Weights

I made some poster weights on commission 4 years ago for a friend who acquired a flat file for his poster collection. I made them out of some scrap blackout fabric I cut off some curtains. I had to hand finish them and it was quite difficult. I made some for myself at the time and wrote it up on Spasms of Accommodation. Since then I've gotten better sewing machines and have learned about cutting 100% polyester with a soldering iron. I thought I'd like to try poster weights again. Maybe my friend could design something neat to have custom printed and I could sew it into weights and put them on my Etsy store.

I tried a rectangle sized to fit a set of weights in a Priority Mail Small Flat Rate Box. It came out 2 1/2" x 5". I immediately didn't like it and dismantled it to use the shot again. I decided to play with a round shape. I finally worked out a design I like and here's how I did it.

First I had to make a pivot attachment for my sewing machine. Lots of tutorials on YouTube say to tape a thumbtack to the bed of the machine. I had two problems with that. First, I didn't have a thumb tack. Second, if I did have a thumb tack the pointy part would be necessarily large and would make an ugly hole in the middle of the fabric. I did have some sequin pins. These are 7/16" long straight pins with a small head. I got myself a scrap of aluminum flashing and made a backing for my pin to make it stand up like a thumbtack. I just held the pin with pliers and banged it with a hammer. When the pin dulled or bent I pulled it out and used another one. I have a bunch. I only ruined about 5 pins making my tack.
Make a fine gauge thumbtack equivalent
After I got the pin through the hole I bent the edges of the aluminum so it would sit flat, taking up the space of the pin head. Then I put a dab of Superglue on the pin head and let it dry overnight.
Pin in the aluminum scrap
I put some masking tape on my aluminum scrap so it won't scratch my sewing machine. I drew some lines on it to help line up the pin where I want it.
Tape applied to aluminum to prevent scratching the machine
I made a little gauge with a scrap of file folder to position my pin in the right place. I placed the card next to my jig and marked 1 1/4" and 2" from the pin so I can get a reliable radius. I taped the outside then moved the card and taped the inside.
Repeatable radius jig

Pin taped down at 1 1/4"
With my pin in place I stabbed it with the leg of some tights I picked up on clearance at Target. This is going to be my secondary containment for the lead shot. If I do a lot more of these I can buy continuous rolls of stockinette on Amazon. They sell it for bandages. 
Circle sewn, opening left for filling
 After I sewed circles out of all the stockinette I had I moved my pin out to a 2" radius.

2" radius set up
I cut some 5" squares of polyester outdoor fabric. With right sides together I stabbed the center on the pin and sewed the circles, leaving an opening for filling.

Here's a close-up of the pin through the fabric. 
I could stick a piece of an eraser on this pin while I'm sewing if I wanted to not stab myself. But it seemed to stay put fine and I only pricked myself once and not that bad.

After I sewed the circle I cut off the excess fabric with my $3.99 Harbor Freight soldering iron. This glass table makes it a cinch to cut and seal these man made fibers.
Cut around the sewn line with a soldering iron
 I use a pair of hemostats to turn the circle right side out. Get cheap hemostats from PJ Tool.
Hemostat helps turn right side out

Turning circle with the hemostat

Turning circle with the hemostat 2

To finish turning I use an 8mm wooden knitting needle

Push the edges out and finger press the seam
Now to the actual weighty part. I found a lot of weights for sale that are filled with sand, which is probably ok, but sounds messy. I also found a lot filled with rice, which is just weird to me. It could attract bugs and it could absorb moisture and make a damp place in your flat file. And aside from that it just isn't that heavy. I like a weight to feel heavy for it's size. I like lead. I want these to be not too fat though, so I'm going to try just half a pound of lead. I tested it to see if it it's enough to flatten a curled up roll of EVA foam. One in each corner will do it, but more is better.
Weigh out half a pound of lead shot
Now back to the inner circle. I cut off the excess fabric with scissors. Stick a funnel in the opening and fill with the 8 ounces of lead shot.
Add lead shot to the secondary containment vessel
The shot just goes right in there. This part is fun.

Poke the excess fabric back in the hole and sew it up on the sewing machine. This is the inside part so it won't show.

Sew up the opening on the secondary containment

I took a picture of putting the secondary containment inside the turned circle but it was blurry. It's kind of hard to get it in there with a small opening, but I like a small gap in the stitching better than a big one that is hard to shape into the curve.

Turn the excess fabric into the opening after the pink lead filled bag is in there. Sew all the way around the edge of the circle so the closing stitches blend in and look on purpose. I use my seam guide at an angle to sew right at the edge of the bag.

Seam guide helps sew right at the edge.
Here's the final product. Having all the lead shot held away from the edge leaves a sort of lip that makes it a lot easier to pick up the circle weight. 
I like this design. I need to get my hands on some more stockinette and some different fabric patterns and see what kind of pretty circle weights I can make. I find weights very handy around the lab. I use my StarTac case weight all the time. That one is over a pound. I may try making some other heavier circles too.