Spokes replaced

[browning]

This is sure to invoke the wrath of the orthodox but that's what I do. I decided to respoke the wheels on my '19 Roadster and built a super duty spoke press and proceeded with the back wheels in the conventional manner. They came out pretty true with considerable effort but I couldn't resist the temptation to try a novel approach. My profession has been in the woodworking industry and I live daily with topics related to moisture content, shrinkage and expansion etc. so I decided to experiment. I oven dried several dozen spokes and redid the front wheels with them. They had shrunk considerably and the process was incredibly easy. The spokes were "loose" between each other, the tenons fit into the felloes much more easily, and the spokes had shortened enough to make the pressing simple. I drilled the hub end and assembled with the outside plate then drilled the 3/8" bolt holes as usual but did the assembly using 5/16 bolts temporarily to allow for shifting as the spokes re-acclimated to their normal moisture content. After assembly I placed the wheel on top of a large round container filled with water and covered with damp (maybe wet) rags to contain the high humidity. In a few days the tapers had regrown to the point of contacting each other and I assumed that the other dimensions had returned to their equilibrium state as well. After the regrowth period I then removed the 5/16 bolts and redrilled and installed the proper 3/8" hub bolts and peened the the backsides over. To my surprise when the wheels were rotated on the spindle there was absolutely no runout visible. I waited a week or so and proceeded to sand and paint the assembly. That was a year and a half ago and the wheels still are the most perfect I have made.

I have hesitated to post until now for fear of the raster and rejection (I have family for that) but thought that some enterprising experimenter might want to give it a try. If you do,I recently baked another spoke to verify the dimensional change. The oven temp was 275 f. and I let it bake for two and a half hours. The tenon shrank .008 dia., the thickness at the hub end shrank.016, the width across the widest part of the hub taper shrank .036, and the length changed .024. Your mileage may vary.

[SurfCityGene]

David, you didn't say what type of wood you used. Shagbark hickory has been said to be the best. Did you have a base moisture content to start out with? Certainly a good idea for wheelwrights to be aware of when whittling out new spokes!
Thanks for posting

[Wayne Sheldon]

No wrath from me! I think it makes sense. The only possible concern I would wonder about is that the heat "might" make the wood a bit more brittle? However, I suspect that 275 degrees F would not not have that much of an effect on the long term strength or resiliency.
It certainly would make the task easier. And likely result in less stress and potential damage to the spokes during assembly.

[speedytinc]

Isnt this the way you are supposed to build wheels? Dry wood put together tight. Wet wood will shrink in a dryer climate.

A well known local past wheel guy didnt oven dry his wood & would occasionally have some loose come backs. Our area has a moderate humidity index normally. I heard tell of a set he built that went to the desert, stored in an attic. After several years they shrunk so much to be unusable. I also had the experience of buying a pair of nos non demountable steel fellow wheels from the east. They were real tight.
As things typically go, they sat in my garage for a year & shrunk. I could have shimmed, but opted to respoke.

Fortunately the guy that took over the local wheel business understands & builds with dried wood.

[KWTownsend]

The wheel guys I know dry the wood to a specific point before turning the spokes. 7% maybe?

[browning]

We buy our hickory from the yards at 7 to 8 percent moisture content which is the correct EMC (equilibrium moisture content) for our eastern inland area. Since the wheels will be subject to atmospheric humidity, being outside, the spokes would naturally expand during the summer months from the point of turning and machining. Oven drying would reduce the moisture content to or near zero and after assembly the wood would normally acclimate to what it would have been regardless of assembly methods. EMC is different for different parts of the country with the deserts demanding drier finished parts pre-assembly and sea shore demanding higher moisture contents to remain stable in those environments.

[George House]

Dang ! Now a third Model T wheelwright in PA David, load up you spoke equipment and come to Texas. I’ll start you off with a pickup load of felloes and hubs. I really like the scientific way you’ve approached and completed your project...

[Rich Eagle]

I am glad you posted that. I hadn't ever considered that. Spokes are a touchy subject and I don't often post what I have done for fear someone will try it and have a failure.
Thanks for bringing it up.
Rich

[browning]

George, Referring to me as a wheelwright would be like calling Jack Benny a concert violinist. I do these things for my own amazement and its always gratifying when they work out. I just don't want to pass on without sharing what I've been fortunate enough to find along the way.

[Rich P. Bingham]

Whatever keeps wooden items fit for use is fair enough, I'd say. Perhaps this may be of interest:
In 1991 I traveled cross country to retrieve a 1922 Packard which had been disassembled in a restoration attempt. The artillery wheels which had been rock-solid in the rain forests of western Massachusetts for 70 years shrank to become quite loose in high and dry southeastern Idaho.

I had read an article in "Fine Woodworking" that told how some ancient wooden artifacts from coastal Pacific Northwest tribes had been stabilized and preserved by soaking in polyethylene glycol (PEG). The theory was that through osmosis, the water-soluble PEG would displace the water content of the wood with the synthetic wax, keeping the items dimensionally stable, and preventing splitting from becoming too dry.

I disassembled the wheels, sand-blasted the hubs and felloes and "primed" them with POR-15. The spokes were stripped of remaining paint, the wheels re-assembled then soaked in water until reasonably saturated. They were then soaked in PEG until the water had been displaced.

Finish posed a minor problem as automotive enamels are not compatible with PEG. The problem was solved by using a water miscible wood primer which coincidentally contained a percentage of PEG in its formulation. The wood primer proved compatible with the automotive finish I used, the final finish turned out very well.

The wheels remained tight and sound as did the finish paint through 25 years until I parted with the beast.

[TXGOAT2]

I have read that Ford dried the critical wood parts to a very low moisture content, then assembled them. That way, the wood was always trying to expand. I'd think the best procedure for wheels would be to make the spokes slightly oversize, then dry the heck out of them and assemble them tightly while dry. If they were good and tight while bone-dry, they'd be very tight under almost any atmospheric conditions short of Death Valley.

[Steve Jelf]

I never thought of this. I'm glad you posted

[Norman Kling]

That seems to be a very good method. It would be interesting to do some sets for various parts of the country to see how they do in other climates.
My uncle used to have a shop in Oregon near Portland where he made small furniture items. We have a few here in the foothills of San Diego County and interestingly some of the joints shrunk about 1/4 inches in our drier climate. That furniture was made from pine.
Norm

[Rich P. Bingham]

When nearly everything was made of wood, rather than plastic, the technology of species suitability for various applications was well advanced and taken seriously. Sadly, that knowledge has fallen into disuse, as well as many advanced techniques of joinery and the seasoning of saw logs.

One thing that bodes well for wooden spoke wheels is the fact that wood changes very slightly longitudinally with changes in ambient humidity. The greatest dimensional change occurs radially.

[speedytinc]

When nearly everything was made of wood, rather than plastic, the technology of species suitability for various applications was well advanced and taken seriously. Sadly, that knowledge has fallen into disuse, as well as many advanced techniques of joinery and the seasoning of saw logs.

One thing that bodes well for wooden spoke wheels is the fact that wood changes very slightly longitudinally with changes in ambient humidity. The greatest dimensional change occurs radially.

It seems I have heard discussed but not mentioned here is that different woods have differing amounts of open cells & closed cells. The closed cells dont expand or contract with moisture. Open cells will. This makes for expansion & contraction, like a sponge. Hickory is one of those optimal woods that are strong & have a good balance of open & closed cells.

[TXGOAT2]

A fiddle maker might have some specialized insight on wood characteristics.

[SurfCityGene]

Speedy, Unfortunately Ralph, RDR, discovered that Oak cracks when it bends or flexes unlike Hickory. I know you weren't proposing using Oak for spokes. Just wanted to make others didn't assume.

[Rich P. Bingham]

It's why tool handles have always been hickory !

[speedytinc]

Speedy, Unfortunately Ralph, RDR, discovered that Oak cracks when it bends or flexes unlike Hickory. I know you weren't proposing using Oak for spokes. Just wanted to make others didn't assume.

Oh no, never use oak. I did mention hickory as the preferred material.
I forget how oak measures up in the strength & open vs closed cell issue, but know it was not good.

[browning]

We have made many thousands of spokes, always hickory. Due to its density it shrinks two to three times more with changes in moisture content than other species, with exceptions. There are actually two rates of shrinkage across the grain. Radial shrinkage of hickory is slightly less than two percent when dried from 8% to oven dry while tangential shrinkage runs about 3%. That would affect tenon diameter and radial fit of the tapers. I was shocked to find the spokes "shortened" by nearly 1/32" at the same time. The fact that the spokes are 9" long account for the shrinkage in that dimension even though the rate of shrinkage was only slightly over two tenths of one percent.

Next experiment is to construct a small vacuum chamber to dry the spokes in. The boiling point of water reduces to about 140 f. at 24 in. of vacuum which would minimize stress, if that was a problem. Thinking of making them available "pre-shrunk" and shipped in vacuum sealed bags for later consumption or to prevent premature expansion while in inventory. I might be looking for a guinea pig to confirm the idea.

[TXGOAT2]

Vacuum drying and packaging sounds like an excellent idea.

[JEC]

would ethylene glycol work in place of polyethylene glycol
Or can you buy polyethylene glycol in bulk?
I bought a nice set of wheels, painted black, for my 25 pickup.
I stored the truck in a car hauler trailer not thinking that it would be hot in the summer.
Its over 110 here in Tucson at times in the summer. Lord knows how hot it was in the trailer.
They all shrank at both ends.
I bought a kiddy pool and soaked them over night and they were back to normal.
a few weeks later loose spokes again.
I would have them respoked but fear that it will happen again.
I may have to go to wire wheels.
I have a set of Model A wheel adapters and wheels but they don't support the wheel hub correctly.
Has anyone made a fix for this problem?

[DHort]

Move out of Arizona.

[TXGOAT2]

Wheels will stay tight in Arizona if they are assembled tightly when very dry. Temperatures inside an enclosed trailer could easily reach 140 F to 160 F.

[Rich P. Bingham]

would ethylene glycol work in place of polyethylene glycol

No. Other than parts of the name, there is no similarity in the properties of the two. PEG is an inert, synthetic wax that is actually used extensively in cosmetics and food stuffs. I purchased a bulk quantity when working with those wheels, but it's been over 20 years ago.

Regarding the storage of your T, temperatures over 100f are also affecting the body framework and other components. It may be worth a chat with other members in Arizona to learn how they care for their Model Ts. Russ Furstnow comes to mind.

[speedytinc]

I conversed with Dave Seiler on the subject. He checks the moisture content of the wood before using. His wood will sit in an area to dry for up to 2 years. Only dry wood gets cut. 6% moisture content max.

Interesting tid bit.
Back in the day, wheel rites would split wood into rough blank form before forming spokes to insure perfect straight grain alignment.

[JEC]

leaving Tucson is an excellent idea; but Mary says no.
any ideas on fixing the model A wheel adapter weakness?
I have the adapters and wheels.