Custom Car Seat From Scratch




Introduction: Custom Car Seat From Scratch

About: Senior VP of an independent oil company. Never met a hobby I didn't like!

In making a reproduction custom car from the 1960s, I needed a totally custom seat for the car. I did some searching for vintage plastic and fiberglass patio chairs thinking that may be what the builder used. No luck. I determined I would have to make the seat from scratch.

DISCLAIMER: this seat is for a custom show car, it isn't intended for daily on-road use.

Tools include

110amp Lincoln wire-feed welder

oxy/acetylene welder for brazing

power hack saw

3/4" rigid conduit bender

4 1/2" angle disk sander/grinder

band saw

table saw

Step 1: Building the Seat Skeleton

The first step was to determine the dimensions of the seat using historic photos. Once that was determined a plywood cradle was built that had the basic contour of the seat on top and fit the car's interior on the bottom. The first photo shows the resulting cradle sitting in the interior with the beginning of the seat's frame set in place on the cradle.

The outside rim of the seat was formed using rigid steel conduit that was bent to shape using an electrician's bender that I bought on Ebay. The frame was made in several pieces and welded together with the wire feed welder to form the outer seat perimeter. Constant trial fitting to the cradle insured a proper shape.

Once the frame was in place back and bottom mounting brackets were cut from 3/4" square steel tubing and welded to the frame. The welds were made wit the parts still in the wooden cradle. The cradle was eventually discarded so a little scorching by the welder wasn't a problem.

A note on welding. The Lincoln welder can weld with wired that has the flux built in or with solid wire and inert (argon) gas shielding. I like to use the latter for projects like this since it results in a cleaner weld without the flux contamination. Either works OK though.

The final step in forming the basic seat was to weld 1/8" x 1" straps horizontally to the frame sides at about 6" spacing to define the seat bucket. the seat is composed of two main components; this frame and bucket and a separate steel insert on which is applied the pleated panel.

These straps were bent to contain 3 flat arms. Two arms extend from the lowest plane of the seat up to the frame and the ends were brazed there. The middle plane is horizontal and is the width of the center pleated panel plate. 1/8" thick white board was stapled to the cradle between these steel straps to further define that panel shape.

This seat has the space-age head rest so a length of 1 1/2" exhaust tubing was welded to the apex of the seat back as a mount for the headrest. A standard 3/4" steel washer was brazed to this tube to hold the 3/4" bolt that attaches the headrest stand to the seat.

Step 2: Fiberglassing the Seat

With the skeleton of the seat built it was time to complete the seat. Another of the myriad uses of good old duct tape is that it makes a great mold for fiberglass panels. Duct tape was applied to the frame between the metal slats to support the fiberglass. 3 layers of 'glas mat and resin were applied on top of this mold. Once the 'glas set, the seat was removed from the cradle which was discarded, the duct tape mold was removed, and another layer of 'glas was applied to the back of the seat to capture and enclose the metal straps and make the seat one integral unit.

Step 3: Making the Pleated Panel Insert

The outer 3" or 4" wide rim of the seat is upholstered with sponge rubber and smooth vinyl. The center of the seat has a panel with a bunch of 3/4" wide pleats. I made this panel from a piece of 16ga sheet metal cut to the shape of the white board used to define the metal straps in the frame skeleton. This panel bolts to the seat with two 1/4" bolts through each skeleton strap. This makes the panel a solid piece of the seat and also hides the edge of the vinyl upholstery around the perimeter of the insert. I used flange-head specialty bolts that I welded to the panel from the top, these bolts have a very large diameter head that when welded to the panel, are invisible under the upholstery padding.

The seat needed some loops on the underside of the frame to accept hog rings that hold the upholstery to the seat. I made these loops by cutting a row of zig-zag strips from a piece of expanded metal available at a steel supplier and welded these to the frame. In that photo you can also see a few of the center panel mounting bolts extending through the seat steel cross-straps.

I smoothed the top of the seat with a later of Bondo sanded smooth.

Step 4: Making the Head Rest

The headrest was made from glued up layers of plywood. Total thickness of the piece is about 3 1/2" and is made in two halves. Once the glue was dry, the two halves where screwed together with 4 countersunk drywall screws and the shape rounded with a 4 1/2" angle grinder mounted with a 36 grit sanding disk. This makes clouds of sanding dust sob I used a dust mask but forming the shape is very easy. Note that the plies in the wood allow the shape to be contoured perfectly symmetrical just following the glue lines.

The headrest needed a way to securely attach it to the seat with a slender 3" tall stand. I built the headrest in tow pieces so I could mount a 3/4" hex nit welded to a 3/4" flat washer that was in turn attached in a hole bored in the top half of the wood headrest with short drywall screws. A 3/4" hole was drilled in the bottom half of the wood so a threaded rod can be screwed into the nut after the wood halves are assembled. This is the core of the mounting stand. To make the external part of the stand I used a length of 1" steel electrical conduit with two more 3/4" steel flat washers brazed to the ends. This stand spans the distance between the 3/4" flat washers in the top of the seat and one screwed to the bottom of the wood headrest. the 3/4" threaded rod is screwed into the head rest, passed through the tubular stand, passed through the washer on the seat top then secured with a nut and lock washer from below.

if left like that the headrest could twist on the seat and not be aligned with the body. To index this piece I drilled two randomly spaced 1/4" holes in the matching flat washer rims and brazed short stubs of 1/4" steel rod into the holes in both ends of the stand. Thus when the stand is installed it can only fit one way into the headrest and the seat.

to make an upholstery mounting pad for the front of the headrest I made two matching sheet steel panels. One panel was slightly smaller than the other and was attaché to the wood with drywall screws. The second panel is removable and clips into the mounted panel using spring steel upholstery panel clips.

Finally I sandblasted the tubular stand and covered it with Bondo. The Bondo was shaped with the power disk sander to a pleasant double tapered shape.

The last picture is the completed seat ready for the upholstery.

Step 5: This Is the Car That the Seat Was Made For

Folks are asking to see the car that this seat is made for. This car is a reproduction of Ed Roth's 1962 Mysterion show car. Strictly for show, it was a run-away hit on the hot rodding scene. Revell even made a plastic model kit of the car that has been reissued 4 times over the years. Unfortunately the car was so poorly built, Ed got sick of the frame continually breaking that he had it torn up and discarded. I fell in love with it as a kid and it was a bucket-list thing to make this reproduction.



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    19 Discussions

    This reminds me of thumbing thru the Car Catalogs and dreaming of my 'PERFECT' '67 Volkswagen Beetle !

    1 reply

    Holy Cow!! That’s awesome!!

    This brought back some old memories. Great job.

    Great seat project. A whole bunch of good ideas to steal. Love the mini TV tucked in the side liner.

    5 replies

    That TV is what Ed used in 1962. Found it on Ebay. It is a true 7" portable but has NO solid state components. That was 1962 before printed circuits, before transistors, even before 8-tracks. The TV is totally vacuum tubes and hand wiring. It is a piece of art itself; no snap together plastic here, the entire chassis and even the name tags are assembled with miniature machine screws, lock washers, flat washers and nuts.


    The Gods must love you for building this,the odds against finding that T.V. must be phenomenal! Even higher when you consider that It would have been an expensive 'state of the art' item when new.

    I had no idea what TV he used so I found a blog (there is a b log on the internet for EVERYTHING!!) and sure enuf someone recognized this one. Delmonico was a Japanese import that he said flooded the US market with cheap imports. Remember when made in Japan meant total junk. Actually this TV shows up on Ebay fairly often, just needed to know that was what I was looking for. The REALLY rare piece on the car that is my biggest treasure is the dash. It is an aftermarket 60s piece that is rarer than rare. I stumbled on it, didn't even know I was looking for it. Have never seen one before or after anywhere.

    Just for info: the Transistor was invented in 1948 and there were already TVs with transistors instead of tubes in 1960 even though they were rare. Also they were in space already in 1960 Telstar by Bell Labs.

    Yep but they were not very reliable and very expensive. There were very few consumer items with them. I have a transistor radio I got for Christmas about that time but I think the folks paid a fortune for it. There were no aftermarket radios at least ones you could afford. As I said, the 8-track stereo was still two or 3 years away when Ed built the car. The radio he used is a big Motorola 120V desktop one!


    8 months ago

    Great 'ible! But from the Department of Picking a Nit-Electrical conduit like in the photos is referred to as EMT or thinwall. "Rigid" is the heavy, Schedule 80 steel conduit that can be threaded like waterpipe. You'd never bend it with that thinwall bender in the picture. End of transmission. Crry on.

    1 reply

    Good catch. Been a while since I spec'd out any electrical work. Forgot the difference!

    Exactly what I needed. Building a rocket to go to Mars, and since it's a long trip, need to make one that is comfortable. Thanks!

    1 reply

    Nice project.

    Do you have any pics of the finished vehicle?

    Awesome! Any chance we could see the rest of the car as well?

    Rat Fink is what really makes it pop


    8 months ago

    Interesting project. I've worked with fiberglass mat (1708) and CSM (1.5) and polyester resins a lot. And it is amazing how hard that stuff gets once the resin is cured. Nice project.

    1 reply

    Yes fiberglass composite is awesome stuff. Strong and hard but very flexible so it needs extra support for something like this seat or a car body. I love working with it too.