1:12 1932 Cadillac V-16 frame and engine

[Roger Zimmermann]

There are good days as well as bad ones, it's life. Today is the second category: yesterday, I did another white wall; thinking there was still enough wax on the mold to avoid issues. There was not, white wall destroyed, fortunately, the mold is not damaged by taking away the sticking white material.
I opened this morning the negative tire's molds. One half is so-so, the other one some tread was ripped away. The material was more or less bonded on the brass at the recess to hold the white wall. Usually RTV is not sticking to metal but this time it did. I have a possible explanation: when I cleaned the uncured RTV , some stayed on the brass and, generally, there was still a trace of that RTV on the whole brass surface. With the proper catalyst added, this uncured RTV acted as a bonding agent between brass and the fresh RTV .
The result: back to the starting line...

[MODEL A MODEL]

Your probably right. I have had similar issues, and you do have to be so careful in cleaning up all residue. I just assume that no matter how thorough I've been, the first or second casting afterwards might have problems. -To save on material, you might try mixing up a lesser amount, thoroughly mixed, proper amount of catalyst, and paint it into your mold or slush it around. -this will cure and peel out like a glove, catching the last of the uncured RTV .

I have had some problem with casting directly with Brass and Copper, as they inhibit the RTV from curing . -if for instance the bulk of rubber cures, but not the surface? that is either uncured residue or surface inhibition.

Good luck! Hoping for more "Good Days!"

[PaulPK]

Too bad Roger. I am not sure why you are using wax on brass. The silicone I used never had an issue releasing from a master. I wanted the silicone to adhere to the brass for sharper details. I only used a release agent when making 2 or 3 part molds so the silicone would not stick to the other silicone parts of the mold. The main issue I encountered was silicone not setting due to chemical inhibition such as sulfurs in clay or certain glues. I found Testors flat, sprayed on the master, made a nice barrier for the silicone I was using. There are many types of silicones as you know and too soft a silicone is not good for complicated parts. I used that type of silicone for casting simple things such as hex wrenches for making nuts and bolts.

[Roger Zimmermann]

Usually a release agent is not needed on brass, but the remains of the previous bad mix did a bond on some surfaces. That's the only explanation I have.
I too encountered no or bad setting due to some material (don't remember which).

[MODEL A MODEL]

Sulfur based clays are a problem, "Super Glues" have been ok, but not if I use a "Kicker"

It is trial and error, word of mouth.

[kon_gee]

Roger,
Unbelievable craftsmanship as I have come to expect from your builds! I have been away from this site for a few years and it is inspiring to return and see what I never thought possible is still actually being created by your hands in real time! Amazing, effort, ability and workmanship!!
I am still blown away by your Lincoln Mark II as well. I actually saw my first Lincoln Mark II in person at the NY International Auto show last week (Elvis Presley's car) and thanks to you I felt like I knew that car inside and out!!

Cheers,
Gary

[MODEL A MODEL]

Continental MkII

[kon_gee]

My bad I stand corrected. The Continental was part of the Lincoln display at the Auto Show and they even had a sign with the Lincoln name on it!! After further research I believe that Continental was purchased by Lincoln after production of the Mark II. So cool to see in person for the first time though.

BTW I am not trying to steer away from Roger's amazing 1932 Cadillac thread.........

[MODEL A MODEL]

It was a division of Ford. Completely its own entity.

A beautiful car.

And Roger's model is superb!

[Roger Zimmermann]

Thanks for the comments!
Yes, the Continental brand was a Ford's division. In 1957, it was integrated into the Lincoln brand. Don't worry Gary: I did the mistake too when I began the Mark II!

[Roger Zimmermann]

It's better to put things aside until better days when it was a flop! As there are enough to do, this is just a temporary set-back. Last month, I began the shock absorbers; it was the right moment to continue with them. The design was more or less performed during the assembly of many parts all silver soldered; this bad method let me do some errors later corrected. As pictured today, they are far from finished, but I'm confident I will have working shock absorbers.

[Roger Zimmermann]

With one white wall every second day, I have now seven pieces. As spares are always good, I intend to do another one. Then, I will have to begin again the tire itself...
In parallel to the white walls, I continued with the shock absorbers. I added some cosmetic details; before closing both ends with the plugs, I did the shafts on which the actuating arm will be attached. When that was done, I silver soldered the blade which should render the shock absorbers functional. By looking at the size of the blade, I doubt that the shock absorbers will be really effective. Well, it's a fun design, even as a failure! The possible movement is about 120°, which is largely enough.
There is a groove on the shaft: a very small O ring (I have some since many, many years) will be installed to prevent the loss of the Hivis. Of course, a closing plate will come at the back of the shock absorbers; some details are still to be added.

[MODEL A MODEL]

You and your giant quarter!

[happyfreddy]

@Roger,
Why so complicated with the white wall tires ??
The color of tires is normally black and at a white wall tire I think only the
outer side of tire is painted white. So why do You not only paint one side.
This would be even easier ....... or not ??
If working correctly You must spend both sides of the tire in white color or not ??

so far very good job ( as usual )......

[Roger Zimmermann]

Yes, Don, I resuscitated my giant quarter!
Freddy: the RTV rubber I'm using cannot be painted. Or yes, it can be, but the paint does not stick on the material! Only one side has the white wall; the other side is black. However, you know probably that at one time, (in the twenties and thirties) the white wall was sometimes on both sides.

Finally, the front shock absorbers are ready. It took a long time to add the latest details; maybe no one would have notice if skipped!
Technically, those shock are ready for the viscous product I have. However, I will ad it when the actuating arm is soldered to the hub. The screw you can see will be the locking system, of course flush with the hub. I assume that the hub and arm assembly was originally pressed on the shaft. As my shafts are inserted from the back, I had to find another solution. The back is now closed by a plate and four 0.6mm screws. A short bearing is integrated to that plate; it should prevent a binding situation for the shaft.
Maybe I will have to add a paper gasket to avoid that the viscous material is oozing.
I cannot finish the rear shock absorbers because I don't know the position of the actuating shaft at nominal position from the frame. The locking screw must be more or less at 90° from the arm and the relation between the actuating arm and inner blade must be right. I will finish the rear shocks when the suspension is done.
I deducted from my pictures the the actuating lever is horizontal for the front shock absorbers; therefore I could finish them.