Roger Zimmermann

People who followed the Mark II construction have already seen something similar with the tires for that model. However, as the memory is fading, it’s a good opportunity to refresh what you learned! January 29, 2010 Success or disaster? That's the day’s question. I will get the answer in one or two days… Some explanation: This day is the beginning of the tire’s fabrication. I’m doing first the preparation for the first negative half mold. The brass tire is put into some plastiline; to have a nice surface, a disc of brass is put on that plastiline. The inner diameter is a tight fit over the brass. (firt picture) Then, the white silicone is prepared with the right hardener proportion. The silicone is put into the desiccator; then some vacuum is applied to that silicone (second picture). Not a lot, about ½ bar ; after that, my hand can’t any more. The picture is not too clear, but the surface is full of bubbles which are bursting one after the other. At the same time, the volume is increasing as the trapped air into the silicone is inflating. Then, the more or less free of air silicone is poured into the can and go back to the vacuum chamber. (third picture) Some bubbles are still coming at the surface, but less than before. I probably did a mistake by mixing the silicone with its hardener because I was surprised by the difficulty to mix both products. The result is that the mass is not hardening at the same rate everywhere. As I had no more space into the desiccator, the first white wall is not under vacuum. (fourth picture) After a long time under vacuum (my poor hands can no more!), I’m taking the « assembly » out of the desiccator. If there are still bubbles in the mixed silicone, they will be squashed by the normal air pressure as long as the silicone is not yet set (fifth picture). The next operation is to remove the plastiline and pure again a next mix of silicone. When this second operation is over, I will then know if the whole process was a success or a failure. At that day, there was like sunshine before the forecasted snow: the wheel covers are ready and I went to the plater to reach them. I’m satisfied at 95%. To avoid that the dull part is getting too shiny, the copper coat was reduced. The result is that on the shiny surfaces, polishing “scratches” can be seen. I still have some black paint to do on them.

The calculation was correct, but another other factor gave me trouble. I will tell what in due time!

January 28, 2010 The answer Tires could be entirely black, but at that time, it was unusual, even if white walls cost extra. The material which will be used for the tires cannot be painted; I had to find a different solution (already in use for the Toronado) by inserting a white ring into a groove made in the tire. The picture below is the mold I will use for that. It's slightly conical to avoid that the ring is coming out. I just hope that my calculation will be right!

You did nice welds. On the pictures, the heat generated is clearly visible; that's the problem with the torch. Doing that welding on a fender or other sheet metal part, you may have a severe distorsion. With a TIG welding, there is also some heat and distortion, but much less than with a torch. During welding, you may put some wet rag near to the welding to limit the transferred heat.

January 28, 2010 Manufacturing the tires Now, I have all the material needed for the tires. The silicone which will be used for the molds had a successful test: strong and does not stick to the brass. I got also the hand pump for the vacuum; this will be needed to eliminate the bubbles crated by stirring the silicone with the hardener. This will be excellent for the hand’s muscles ! Now I’m doing a job which is necessary. The brown mass is paraffin. For what this could be used ?

January 13, 2010 The « under wheel covers » were easier to do, even if the thinner material (0.2mm) gave more trouble that the brass used for the wheel covers (0.3mm). A completed wheel cover is on the first picture; it is attached on the wheel with a system which came to me during the night. The system is shown on the remaining parts: these parts have the same shape as the main wheel cover because they were done with the same tools. I flattened the outside surface at the end of the apertures; this way, the wheel cover with stay on the wheel. Sure, this system will damage the paint, but real wheel covers do the same! The apertures have a specific usage: I will soft solder the parts to the wheel covers through them. Now, I just have to polish the parts, let sand blast the recesses (I came away with silver painting) and let chrome the wheel covers. January 19, 2010 The wheel covers are now polished and almost ready to be chromed. Almost ? Why ? Well, I have to cover with masking tape the surface which will be shiny. Once the task done, the plating company will media blast the surface which will be dull. Once the masking paper away, the tree with the wheel covers will go into the various bathes. The copper wires have been soldered before the masking paper was set on the parts to avoid that the glue is burning.

Cutting fluid would also prevents the overheating. I suppose the suds are not hardened but made with a strong steel.

Are you not concerned that the dust creating by grinding may land on the polishing wheel? Some protection on it when not in use could be appropriate.

Thanks Mike! What I'm doing is quite different than your present restoration!

January 07, 2010 The five basis wheel covers are ready to be reworked. The part in the middle is a prototype; its outside diameter is too small ; he will not be used but it was a good part as an exercise for the apertures. January 12, 2010 All wheel covers are now ready. All five parts are not really identical: the holes have been done with various files, therefore variations are not avoidable. The small part on the second picture is a male shape of the holes and was a good help to have them more or less identical. The distance between the apertures is not absolutely the same on all pieces; there are differences between 0.1 and 0.3mm. I spend about 1 hour for each aperture…

December 19, 2009 The primary reason to refresh the model was the wheelcovers and that will be almost the last task! One of the reasons why they are coming that late is because I was unsure how to do them. Some explanations are needed, but with a view from a real wheelcover. The 5 parts which are dull are slightly in recess compared to the chromed part. I could have cut some silver tape and glue them on the disc but they would be higher than the disc! It was a solution which did not please me. To stamp the wheelcover with the recess was not possible with the tooling at my disposal. Therefore, I designed the part in two pieces: first a cover less the dull parts and a second cover soft welded behind. The recessed parts can be then painted silver. I’m doing first the dies for the first part which implies a lot of work with a hand held tool as both parts must be well adjusted. A first part is shown with the tools. The large tube is needed to guide both dies. The part is obtained by pressing a thin piece of brass between both dies. The excess material must be removed and the 5 « holes » must be done.

If I'm understanding well, you are still welding with oxygen/acetylene? I learned the process more than 50 years ag; I'm not sure if I still could!

December 12, 2009 As slick tires are not recommended for passenger cars, I have to add some thread. As I could recover enough bands from the Toronado master tire, I began to soft solder the bands one after the other on the piece of brass. The first one is soldered entirely ; the second one is at about .6mm from the first one. To have a constant distance between both and to help maintaining the band on the master tire, I’m adding pins at various places because I cannot held the assembly with hand during soldering. About 5 minutes are needed to heat the brass with the soldering iron; after that heating time, the solder is flowing at both parts. Once all is soldered, the excess tin must be removed. Manufacturer’s name and dimension must be added to finish that master tire. December 14, 2009 It seems that Gerald Wingrove gave me the inspiration decades ago to add the inscriptions on the master tire with first praying some surfacer, writing with a pen the name or dimension and scratching the unneeded paint. It’s not an easy task, but it can be done. With tools from a carver, it would have been possible to cut each letter and attach it to the tire. With a CAD machine or a 3-D printer, the tires were already done!

Keiser31, it seems that you like it!

December 09, 2009 Master tire The first operation is to remove the brass bands which are soldered to the main « tire ». I hope to salvage most of them. The master tire is coming on the lathe to modify it: a bit lass tall and narrower. Most of the work is done with the conventional tools belonging to the machine; the sides are modified with a hand held tool, like you would do with a piece of wood. The difference is that the metal is harder to cut! The job is quicker than anticipated; the master is more or less ready: I have to add the bands for the profile and do the name. The groove on the side is for the white wall. It will be made with silicone and pushed into the tire. To do that groove, I used an improvised tool, very thin (the black arrow is showing it) ; due to its shape, that tool created a lot of vibrations. To maintain the white wall into the tire, the inside diameter of the groove is larger than at the outside.

December 06, 2009 All five wheels are ready. Two are seen at the back and the other ones at the front. The next step: either the wheelcovers or the tires, I don’t know yet! Regarding the tires: in contrary of my plan, I will do the tires for the Avanti first (at that time, the Continental Mark II was still in planning). The exterior diameter of the Toronado master tire is almost the same as a tire 6.70 (which is the tire’s dimension for the Avanti) but too small for a 8.20 tire for the Mark II. December 07, 2009 I began today to modify the Toronado master tire. Compared to what I must have, it’s too wide and only 1 mm too tall. The white wall was very thin for the Toronado; it will be wider for the Avanti. I regret that the name « Good Year » will be destroyed with the modification. As usual, I don’t remember how I did it, but by looking carefully at the letters, it seems that I painted the surface, scratched the unneeded paint and added some with a brush to have more thickness.

November 30, 2009 Not yet finished… ...and already something to repair? The hub from the front brake rotor is 0.1mm too large for the hole at the wheel center. It can happen when there is not enough precision! I had to remove the caliper to modify the rotor. For practical reasons, I could not enlarge the wheel’s center hole. Now, I have to do the same at the other side! December 01, 2009 The first wheel is ready. I had to modify the inside diameter because there was an interference with the caliper. I just have to finish the 4 other wheels, fabricate the wheelcovers and the tires!

Many years ago, my father was a strong smoker. While driving into the car from my sister, they had an accident. As a consequence, my father had difficulties to breathe. He stop smoking from one day to another.

November 23, 2009 After almost swimming into metal chips, I finished the 5 rims and began to do the wheel’s centers. November 27, 2009 There is a lot of hand held tool work, especially at the rear of the wheel’s centers. I have to be careful with the fingers and with the tool. There are vibrations and, if the tool is not held correctly, it can get stuck into the part to be machined. The secret with this kind of work is to take away a maximum of metal but leaving enough to have a stabile part.

That's true. It's not ecologic nor efficient, but I cannot do differently. You will see again later when I will relate the construction from the fame and engine from the Cadillac V-16!

November 11, 2009 We are continuing with the rim work: I’m now turning the inside diameter. There are bits of brass everywhere ! The machining of the rim is coming well along. On those parts, angles are never at 90°. The small tool is perfect to machine such surfaces at odd angles. They must be recorded to facilitate the work at the other remaining parts. The first rim is completed ; the weight is just 21 grams. For the 5 rims, I began with a 1 kg tube! Yes, there is a lot of waste.

Welcome back! The trim is good looking.

November 10, 2009 Something entirely different… ...but still for the same model: THE WHEELS! Not long ago, I bought some brass to do the rims; unfortunately, there was no tube available at that time, I took a plain stock. That bit of brass is heavy : 1 kg ! The beginning is to reduce the outside diameter from 40mm to 35mm. Due to the nature of the lathe, I cannot take more than 0.5mm each pass. If I’m taking more, there are too many unwanted vibrations. Once the outside diameter done, I will saw 5 slices a bit more than 13mm thick. They will be about 110 grams each. Once each rim will be ready, their weight will be just some grams, but I will have a mountain of metal chips!

October 28, 2009 As I’m waiting small bulbs for my 57 Brougham (scale 1:1), I decided it was a good opportunity to glue the back window. I used instant glue to attach the window to the body; the molding is glued with transparent silicone. As the setting process is rather long, some tape was used to maintain the molding. When set, I will be able to remove the excess silicone; then I will be ready to glue the side emblems and the name plate at the trunk lid. The end is near !

Thanks Paulie! I just noticed that the quality of the last picture is discutable...