21" demountable split rims
Should I fill this, or leave it as is? I'm taking a rim to the local club meeting for some opinions. The person I bought it from is reputable, and said they will be fine. I was thinking of filling with Lab Metal, but someone else mentioned just use duct tape(?)and a flap. The edges are not sharp, and they are quite sturdy.
Second, the 21 X 4.50-4.75 Universal tire or the Lucas 4.50 X 21 are the correct tires, yes?
(I just noticed you can see the latch on the far side. Wow, my phone camera has great DOF)
I thought my rim would be OK showing pitting rust, split open like opening a ring top can.
Often rims has a bad area where they have been in contact with the ground for too many years. If you haven't got any area on the rim with more damage than what you show, then I think it'll hold up fine. The talk about sharp rims cutting tires only applies to clincher rims, for 21" rims you just need to assure enough structural integrity to hold the tire in place. Tire pressure is lower than in clinchers, more like modern cars. Flaps are necessary for split rims of this type. Any 4.50"x21", 4.50-4.75x21" antique car tire will work I think.
I have seen Frank's pic twice on my own car. I have also had a few lugs come loose. No more pitted rims for me. If you can't see the original swaging of the lugs due to rust, it's too thin to run safely. Either the rim will split or the lugs will pull out of the rim. Neither is good.
As the Model T part most exposed to rain, dirt, mud and water for at least 85 years, it is very difficult to find original Model T rims that don't have some degree of pitting. 44 years ago, all five of my rims looked exactly like Chris's and 44 years later they still look like that. I would not hesitate to use Chris's rim. It appears to be very thick and very usable. No need to fill it. The bondo or filler would add nothing to the the rim in regards to strength and it is all concealed anyway. The pits look relatively smooth, but if you can feel any sharp areas, they should be ground smooth. I would also use a flap to line the rim so as to protect the tube from any sharp areas that may have been missed. Jim Patrick
Chris, your rim looks fine to me. The problem with the split side of the rim Frank shows usually occurs near the join in the rim, because that's where the water gets in and causes rust, to the extent that the rim becomes thin and weakened.
On this type of rim it is correct to use a flap in the fitting of the tyre. The flap is there to isolate the tube from the join in the rim to avoid chafing and to keep any rust flakes away from the tube also.
Hope this helps.
Allan from down under.
All my rims look like yours. When I change a tire, I go over the inside of the rim with a stiff, short bristle wire-brush and clean it up as best as I can, then hit it with some Rustoleum and when dry, add a layer of duct-tape with several inches of overlap.
But my tires are clinchers, which, except for perhaps a quarter or half-inch down the middle, protect the inner-tube from abrasion. If you're working with balloon tires, you may benefit from being a bit more proactive about protecting the inner-tubes. Fortunately, tight-fitting, rubber liners (which are unlike loose-fitting clincher flaps) are available through most of the big catalogs.
A word about where to buy tires: Fresh rubber has an unmistakable odor and when you smell it, you know your tires will not dry out and crack before they can wear out normally. Lang's is adamant about their customers receiving the freshest stuff possible, so they "drop-ship" the tires to us directly from the manufacturer. While you're on the phone with them, make sure you're getting the right size tire.
If it were mine, I would only fill the outside of the rim, especially the side facing the outside of the car, for cosmetic purposes only. If the pitting is no worse elsewhere on the rim than what shows in the picture, it is probably useable. Check all the lugs to be sure they are tight. I use flaps inside my tires and only pump to 35 lbs pressure for the balloon 21"tires. So far I have had no problems.
Dave has a good point about the pitting eating into the weld holding the lugs on. If the pitting inside the rim has compromised the integrity of the weld, It wouldn't hurt to recess the area around the lugs with a grinder where they attach to the inside of the rim and apply weld to the recessed area and build it up with weld over the end of each lug on the inside of the rim, then grind flat. Jim Patrick