Structural wood - same for seat frame?

[a griffin]

What is the preferred wood you use to build seat frames and bolsters? 

When replacing structural wood, I have used primarily Ash. It tends to be a strong, sturdy wood and wonder if it would be the choice for seat frames or would you lean towards a different species?

I'm working on a 30s Lincoln, but your experience on any make from the 30s would be helpful.

The original seat frame is gone and I've been fortunate enough to have a loaner frame from another car to use as a template. The loaner frame was built in the last 25 years and is a mixture of oak and pine, so no help there.

Edited November 1, 2022 by a griffin (see edit history)

[Walt G]

Use ash, you need the strength just as you would for structural body wood.

[Bhigdog]

Ash is  light weight and strong but it does split easy. Just sayin.........Bob

[Akstraw]

You won’t go wrong staying with ash.  I have used ash for the seat structures on several cars.  I do have one period reference that suggests oak or birch as alternatives.

[DFeeney]

I have heard Oak is hard to nail

[wayne sheldon]

I have worked with wooden structures on several of my own restorations, as well as helped a little bit on a few friends' restorations. In addition to that I have discussed this subject with several people that have done a lot more such work than I ever will! All that said, I am NOT an expert on the subject.

One thing I know. Back in the era, a lot of other woods were used besides ash. What woods were used depended a lot on the application, the stresses the piece would be expected to encounter? How much weather exposure it may have? Whether a fine finish paint was needed? Along with ease of workmanship in the factory setting?

Over the years, I have seen ash, oak, mahogany, poplar, pine (believe it or not!), and even various fir. I have seen the inside of numerous model Ts, and seen that not all bodies got the same wood in the same place as all other same body style! I have been told by restorers of both Nash and Buick multiple cars that they also used differing woods from one car to the next. I suspect that was common throughout most of the industry during those decades.

Regardless, ash is a good choice for most applications in most era cars.

When I re-wooded my 1915 Ford model T runabout (on a very tight budget!), I used mostly whatever I had that was appropriately strong. I had some oak and poplar left over from a previous restoration, mahogany salvaged from old furniture, and some incredibly strong old house floorboards I don't know what they were. If I can get some time needed to finish the restoration I will be very happy with it!

 

A related tale.

Many years ago, I was restoring my 1925 Studebaker coach. It was mostly a very solid original car, requiring a mostly cosmetic restoration. One original running board was in very good condition, needing only fresh covering. The other running board had apparently been hit somehow, nearly a third of the wood was broken off and missing. I knew enough to know the wood was not oak or ash, or any other usual hard tight grain wood. There was a specialty lumber store well known in the area (sure miss those days!), so I took my broken running board over there. The fellow in the shop takes one look at it and exclaims "WHERE did you get THIS?" He then rattles off some fancy name I had never heard before and tells me it hasn't been commercially available since before World War Two! He also tells me that there is one lone grove of this wood known back East and that if I wanted some of it, he MIGHT be able to get a small amount, for a significant price. I told him that an exact match wasn't really necessary, and answered his question of where had I gotten it. He then told me that the closest relative of that particular tree which was still commercially available was---(drum roll please)-----Douglas Fir.

Very careful selection of the best grain board readily available and I had a nearly perfect match for my running board.

[chistech]

I do a lot of rewooding of both bodies and seat frames. I use primarily ash but in some instances have started using 7 ply ash veneer plywood. A perfect example of where I would use the plywood is in a side panel of a seat frame. Originally, this was a large panel made from solid wood (mostly ash) jointed together, often in multiple areas, then supported with an iron to help hold the whole piece in place and together. Using the plywood here is a better choice simply for the strength with the iron being replaced simply for originality. With the upholstery covering the end grain, there is no visible difference. Of course, anywhere the end grain is visible, ply is not the choice for originality. My work consists of mainly 30’s GM cars so front seat frames that are completely covered are-so much stronger using plywood. I use the ash ply because it’s full dimensional and 7 ply. It’s not cheap in construction or it’s cost with a 4x10x3/4 just costing me $250. I use this same ply for the floor boards also as it was originally used on these cars. 

[1wonton]

Ash is good but I personally prefer Maple or Cherry; both are easier to work than ash.  Neither has the bending strength of Ash but are quite adequate for car frames/bodies.  Never use Oak as it reacts to wet environments.

[wmsue]

I replaced the front windshield header and two door headers in my Whippet Cabriolet with Ash a few years ago.

Interestingly enough, the originals were not made from Ash. If I had to guess, I would say Elm was used originally.

I found an article in a publication of WOKR (Willys-Overland-Knight-Registry) that answers a question regarding what type of wood to use.

 

On 11/11/2022 at 10:39 AM, 1wonton said:

Ash is good but I personally prefer Maple or Cherry; both are easier to work than ash.  Neither has the bending strength of Ash but are quite adequate for car frames/bodies.  Never use Oak as it reacts to wet environments.

I've always felt that Oak (especially white oak) was a good choice for damp environments. Not as good as Teak, but still a great boat building wood.

 

 

I think it may be more important to look at the grain and structure of the wood you use. Look for dense heartwood and close grain. Wood from 50 or 75 years ago differs very much from wood you find today. Because of climate change and forestry management, we are seeing a much different product now.

 

 

Bill

[John Kelso]

Its a Lincoln! My three all use ash, everywhere in the structure.

[wayne sheldon]

JAK, What body builder for your Lincolns?

 

Just me being curious. Besides, I know a bunch of model L owners. 

[John Kelso]

Brunn, Murray,and Le Baron. Le Baron is 3rd in quality of build, in my opinion.

[chistech]

I have to disagree with using white oak for car body wood and oak in general. Oak has a very porous, straight grain. For boats, constantly exposed to moisture, white oak is a good choice. For our cars, where the relative humidity is the prevailing moisture exposure, white oak is much to reactive to the changes from dry to moist. I’ve built a lot of white oak furniture and have seen 3’ pieces shrink and grow 1/8-1/4” in difference. This is not acceptable in car bodies. Ash is much more stable when it comes to the climate conditions. In wood bodies, especially trucks I’ve seen, recreated in oak, suffer extreme changes due to humidity. Open frames like depot hacks and door-less “C” cabs get away with it but you will notice purposeful joinery and hardware placement/design so that the expansion/contraction has less effect on the body. Vehicles in oak with oak doors are a no-no. 
      Yes, wood has changed but mainly because wood 75+ years ago was primarily old , natural growth, and not subject of today’s scientifically designed fast growth species. There is virtually no old growth wood left in common lumber species.

[Restorer32]

Oak in the body is the kiss of death if you ever hope to sell the car in the UK.

[a griffin]

Thanks for everyone's input. 

I will be building the seat frames out of Ash.

[Str8-8-Dave]

So I replicated the front seat frame for my 1931 Buick 8-66S in ash lumber with birch plywood sides.  The old frame was pretty complete but so weather beaten as to no longer be sound enough to use.  I also inventoried the fastener hardware before I disassembled it to allow individual pieces of wood to be used as patterns.  I had no way to make mortise and tenon corner joints so I doweled the corners.  

 

The more interesting project was "creation" of the rumble seat back frame, which I didn't even know existed until Dave Dunton in Georgia, who owns a 1931 8-66S, was so kind as to remove his rumble seat back exposing the wood frame.  I made the poor guy supply a million pictures of his seat back frame and fill out a dimension form from which I vicariously built my seat back frame.  The side frames of the frame were steam bent 4 inch wide pieces of ash lumber with a finger joint that I had no way to make so I bought a band saw and pieces of 1 x 6 ash dimensional board and cut 4 profile pieces 1 inch thick and glued them together to get a 4 inch wide curved side frame.  You can see both projects at the following link.  Front seat project is on pg. 3 of 4 in a post dated 11/20/2020, rear seat back frame is on pg. 4 of 4 in a post dated 11/22/21.

 

My 1931 Buick project- the saga begins... - Page 4 - Me and My Buick - Antique Automobile Club of America - Discussion Forums (aaca.org)