Homemade long spring saddle for under $15

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I got the leather cut and wax hardened. It was hard from just the regular wet and dry hardening but after the wax cooled it is almost like plywood.

I cut it with a razor knife and it fit perfectly. I held in place for the cutting with clamps.

Wax hardening makes it a nice dark brown. The pox marks are from the Bondo scratch filler. The scratch filler also gave the leather a pink stain on the pox marks. If you do this fill in any imperfections in your female mold with plaster. The ACME logo embossing is very shallow and light because a lot of the depth came out with the pressing and heating for the wax saturation.

The dents in the side of the leather are from plaster cast areas that I did not smooth out well. I thought it was smooth, but it wasn't. I used the Bondo scratch filler here on the sides and it must expand when it is wet for a few days. It also discolors the leather (it came out darker after the wax saturation). The leather picks up every nuance of your mold so I learned to be more careful if I do this again.

The leather also shrunk a little with the hot wax hardening. I will have to grind a little off the pan to make it fit. Next step after fitting it to the pan is to sand the leather to make more rounded contours as the razor knife left some small angles instead of contours. It should look old when it is finished.
 
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I am making another long spring saddle from a Japanese saddle and a child's sidewalk bike with long springs. I made the mold out of concrete with a little plaster to build up the lip. The plaster came off the concrete so I Gorilla glued it in place. A 60 pound bag of concrete is under $4.00 so it is way cheaper than plaster. You could make your mold from this and save $.

I used the seat with the original cover on it to make the mold. I then stripped the original cover and padding and replaced it with a gel pad from an old seat cover that came on one of my free bikes and added a little thin closed cell foam to the saddle sides. The foam was from the hobby store for $1.00. I used scrap upholstery leather that I soaked in water for several hours prior to clamping. The pressure from the clamping squeezed the gel down along the back side of the saddle and made lumps in the leather. The gel pad was thicker than the original padding and caused distortion problems. The pressure also embossed the original diamond pattern from the vinyl seat cover into the leather. The problem areas where wrinkles develop when recovering a seat have been eliminated with this mold method.

The wrinkles in the back and the sag in the side are from the gel being squeezed down by the clamping. This is a learning process for me. I think you need to use traditional thin closed cell foam to get this right. I plan to try this again with another piece of leather after trimming the lumps off the padding. I may eventually work out the bugs and get this right. Notice the smoothe contour along the bottom of the saddle - no wrinkles.

Air bubbles in the concrete mold are filled with plaster and sanded.
 
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us56456712 said:
The dents in the side of the leather are from plaster cast areas that I did not smooth out well. I thought it was smooth, but it wasn't. I used the Bondo scratch filler here on the sides and it must expand when it is wet for a few days. It also discolors the leather (it came out darker after the wax saturation). The leather picks up every nuance of your mold so I learned to be more careful if I do this again.
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Great work so far, I don't mind the imperfections (if that's what you want to call them) as it gives it a more vintage/used look
 
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cman said:
Can you vibrate the mold as it is sets? That may help with the air bubbles and voids.
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I tried hand shaking and banging on all 3 molds. I may not be making my plaster runny enough. It sure sets fast. Plaster and concrete both gave me air bubbles, but less with the concrete. It was easy to plaster fill and sand out the bubbles on the concrete. I even tried smearing plaster on the male part first, which was worse as it left big cavities. I am doing something wrong but the only other plaster molds I made were for foam duck decoys about 20 years ago and I don't recall having bubbles but who knows what tricks time plays on the mind? The only thing I can think of I have that vibrates is my snow blower. Any Ideas for something that vibrates? My plaster decoy molds was where I got the idea for the seat molds.
 
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Finished:


I am working on 2 more. I am spending more time on the mold for the last one. I have filled in all the imperfections in the mold with plaster, not scratch filler and resisted the urge to use spackling. I smooth sanded it to hopefully get a better result. I doubt that will make any more, just an experiment that I hope gets the bugs worked out by the time I am done. Should be finished by the new year.
 
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us56456712 said:
Finished:


I am working on 2 more. I am spending more time on the mold for the last one. I have filled in all the imperfections in the mold with plaster, not scratch filler and resisted the urge to use spackling. I smooth sanded it to hopefully get a better result. I doubt that will make any more, just an experiment that I hope gets the bugs worked out by the time I am done. Should be finished by the new year.
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You know I think this seat came out just fine!
 
Here is the earlier seat I posted for which I also made a mold. The spring assembly will be bypassed and the seat guts will be attached to the original road type rail. The long springs in this case will be for looks only. the spring assembly is from a child's long spring sidewalk bike saddle that the pan had rusted to tin can thinness. A modern road seat shell and leather scraps from the Goodwill Store complete the parts. I want to put this seat on one of my Klunkers and don't want the rocking and rolling that is associated with springs. I tried an old spring saddle on a Klunker and it was way uncomfortable.

 
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The original saddle that was gong to cost me under $15 ended out about $50. The two seats it was made from were from free bikes. Paint, hardware $25 for the leather all add up. This one pictured below is a genuine under $15, but only because I already had an old girls saddle and another free saddle as a top spring donor. I just threw it together to clear out the house for Christmas. It's too cold to build in the shop so I use the kitchen table and bathroom. You can only do this cheap if you have free donor saddles and scrap leather and an old closed cell foam exercise mat from the thrift store. Here is the under $15 model. Not as nice as the first one.

It will go on my bar bike (below). The seat quality will fit right in as the bike is a real maggot . The bar bike has a free saddle on it that came from a junk bike someone gave me. It has potential for modification to a long springer so I will keep it.
 

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