Technical/practical upholstery question 31 Buick 8-66S rumble seat cushions

[Str8-8-Dave]

Hi to all;  Anyone who follows my posts is probably aware that I am making a reproduction wood seat back frame that attaches the seat back springs/cushion assembly to the rumble lid.  This part was missing outright and I was able to reproduce it with Dave Dunton's help and generous sharing of information about his original 8-66S rumble seat cushion assembly.  

 

Before I knew the wood frame was missing I installed bare base seat springs on the floor of the rumble compartment and when I had the seat back springs incorrectly attached directly on the rumble lid woodwork there was enough clearance between the seat springs on the floor and the seat springs on the rumble lid that the lid closed successfully.  Now the seat back springs are attached to a correct wood frame.  And guess what- now the lid won't close because the bare seat back spring now overlaps the base seat spring and they collide when you start closing the lid.

 

So here is my question:  Is it reasonable to assume the offending springs can be compressed, either with fabric straps or with a seat cover design that compresses the springs to gain back the required clearance to let the lid close?  See pictures below... 

 

This first picture was taken before I knew there was a wood seat back frame missing in the car.  Where the red arrows are is where the trouble is when the seat frame is incorporated.  Unlike this picture where the bottom cross wire of the seat back spring just clears the back cross wire of the base spring, the bottom of the back spring now hangs about 1 inch over the top of the rear of the base spring and the lid can't be closed.

 

 

This is what the seat back frame looks like mounted on the rumble lid

 

And this is the back spring mounted on the new frame.  The bottom perimeter wire of the seat back spring hangs over the rear row of springs on the base cushion springs.    

Edited November 14, 2021 by Str8-8-Dave
Add pictures, descriptions (see edit history)

[Mark Shaw]

The short answer is YES.  Springs can be compressed to form a contour to the rear of the seat that will also be more comfortable for passengers.

[Hubert_25-25]

Dave, 

    First of all excellent work.  Are those spring assemblies new or how did you clean them up so well?   Second, the rear of the seat base spring has to be compressed when you install it to get it under the seat back spring.  My 1925 Buick is similar.  The seat back is upholstered to the car - or not removable.  The frame is actually only held by webbing straps along the top of the spring seat back assembly. Once upholstered it is all held in place but can compress.

I do have to fight installing the seat base as my tool storage is under the seat.  The seat base spring is taller than the gap under the seat back.  So step one is to compress the back of the seat base and shove it under the seat back.  The seat base is slid back until the front edge clears the painted metal band at the front of the seat riser.  That metal band is what keeps the seat base from moving forward.  You are actually compressing both the back of the seat base and the base of the seat back at the same time.

When this is upholstered it will all work correctly.      Hugh  

 

    

 

 

Edited December 21, 2021 by Hubert_25-25 (see edit history)

[Str8-8-Dave]

6 hours ago, Hubert_25-25 said:

Are those spring assemblies new or how did you clean them up so well?   Second, the rear of the seat base spring has to be compressed when you install it to get it under the seat back spring.  My 1925 Buick is similar.

Hi Hugh and thanks for your reply.  The seat springs you see in my pictures are reproductions and modified ones at that, they are intended for the rumble seat compartment of a Chevrolet rumble coupe, my car is a Buick and the width of the compartment is a bit narrower.  While your info is good for the front seat the questions I had that are now resolved are for the rumble seat, not the interior seats.  Spacing for the rumble seat base cushion to the back cushion is different because they cannot be allowed to drag on each other as the rumble lid is opened and closed.  I got this all straightened out by working with Dave Dunton in Georgia who has and identical 31 Buick 8-66S rumble seat coupe that had original seating in amazingly good condition to use for an example.  His rumble seat back is removable from the rumble lid and so is mine and there is a gap between the top rear of the base seat and bottom of the back cushion.   There has to be clearance there and there has to be clearance from the face of the base seat to face of the back cushion when you close the rumble lid or it won't close.

 

Thanks.

Dave

[chistech]

The rumble seat cushion and the rumble seat back cannot be overstuffed and the covers themselves require compressing the springs quite a bit. When I did the rumble seat on my 32’ olds I too could not close the lid with the springs in place uncovered as they would interfere in exactly the same place you’re showing. The cushion cover was difficult to install because the spring set needed to be compressed quite a bit which I accomplished by putting a 2x6 plank across the cushion and pulling it down with two bar clamps to my bench. I flipped the cushion springs with the padding and upholstery upside down, then put the 2x6 across lengthwise clamping the ends down with the bar clamps to the edges of my bench. This allowed me to pull the upholstery down and under the spring frame so I could tack it to the wood. The seat back upholstery needs to go on tight also and should have a slanted bottom. When the seat is open there is a slight interference fit but the upholstery slides on itself and allows you to close the lid. If that junction of the cushion and seat back wasn’t that tight, it would offer to much of a gap when sitting in the seat making it very uncomfortable. 

[Str8-8-Dave]

16 hours ago, chistech said:

The rumble seat cushion and the rumble seat back cannot be overstuffed and the covers themselves require compressing the springs quite a bit.

This is kind of what I concluded from just monkeying around tying springs with zip-ties.  I have mine tied to give about 1" clearance from bottom of seat back spring to back of seat base spring un-covered, no upholstery.  I figured there could be just enough padding under the seat cover in that area to close the gap between the 2 spring sets. 

 

My big fight for now is my upholsterer is working on the interior seat which was originally covered in real mohair and will likely be covered with 100% polyester plush velvet faux mohair.  I gave him some material I got with the car that matches the rest of the interior trim and he says I'm about 2yrds short of a happy meal.  This stuff is hard to find if it has to match.  I've got a bunch of samples coming from various vendors.  If I can find some that is close I will order 6 yards so the whole seat and frame can be covered in one material with a little left over...  

 

 

 

Edited December 30, 2021 by Str8-8-Dave (see edit history)

[chistech]

Could you let me know what suppliers you are working with? I have a 30’ chevy 4dr I’ve got to find material for. Hopefully somebody can get it faster than one or two years which seems to be the normal these days.

[chistech]

Here are a few pictures of my rumble seat back and cushion. Notice the top edge is also slanted to clear the front edge rain gutter when closing. Another picture shows a rumble seat back in a 32’ olds that was done by a custom upholsterer. The top of the cushion is too high and it makes closing the seat very difficult. It is also cloth rather than vinyl like the originals so it doesn’t slide on itself as easy. My cushion upholstery was too small and it shows it in the picture. I went to Lebaron Bonney and worked with them to get it right. It seems they had three different size patterns in their system for the same cushion and they used the first pattern that came up on the computer. Turns out it was the wrong one. My cushion got recovered after this picture with the correct size upholstery.

Edited December 31, 2021 by chistech (see edit history)

[Str8-8-Dave]

So as far as vendors go I am working with Mac's/Eckler's, Kovi and The Fabric Co St. Louis for samples only, I'm not sure what I will get.  SMS is supposed to be the best but I had a go-round with them and my trim shop guy has had issues as well so I'm a little shy about going there.  

 

Your seat back frame and springs look quite similar to mine.  Amen to the slanted top, my springs are tied to give that angle and when the cushions go to the trim shop I will make sure my trim guy knows there are certain boundaries he can't cross if the cushions are going to work.  I'm surprised the Olds rumble has cloth instead of either leather , vinyl or Naugahyde,  rumble compartments are notoriously wet places for seat trim to live in.  

[chistech]

That olds was fully upholstered out in CA for less than $4000. The guy did a nice job in most areas but he used the wrong material in the rumble as you noted and made the profile of the rumble back rest wrong. Not sure this was fixed after these pictures were taken. I understand the gentleman who owned it lived less than six months after it was completed unfortunately. It’s a very nice rumble seat car and the second rarest model of 32’ Oldsmobiles.