What's in a wheel - Part 2

In this post, I will discuss how I made a mold.

 

Step 1, acquire a decent condition wheel (the plastic part) to use to create a mold:

As you can see from this picture, some of the banjo parts are broken, but the wheel is essentially intact. This wheel came off a '37, but it's the same size, so as a mold, it should work perfectly. Finding this wheel was a stroke of luck. I happened to check eBay on the last day of the auction and picked this up with no competing bids for a really low price. After I'm done, I will either repair the spokes and re-sell it or just sell it as-is and make my money back.

 

Step 2, acquire some liquid silicone rubber to make a mold of the aformentioned wheel:

For this, I opted for a product by Smooth-on called OOMOO 30. It is a 2-part liquid silicone with a fairly thin consistency which doesn't require a vacuum chamber to degas it. It's designed specifically for amateurs and hobbyists. 

 

Step 3, make the mold box:

 

 

This part was the hardest thing to consider. I was envisioning either making a square box which would waste huge amounts of silicone or require some kind of filler. Or, I would spend weeks or months making a segmented wooden box with lots of small pieces. Somehow, I never considered other materials until I saw a video where someone made mold boxes out of foam board. The dollar-store had the thin stuff which worked quite well to make a round box seen here. The hardest part of this was applying the hot glue to the bottom thick enough to seal it but quick enough to put it down before the glue hardened.

 

 

Step 4, pour the first half of the mold:

For some reason, I don't have a picture of the first half poured, but here's a shot of the first batch mixed up. You need to really stir this stuff until there are no more streaks. Otherwise, it won't set properly. Oh, and plan to have more than you think you'll need because I needed twice as much as I thought I would need for half the mold. In addition, you should also set up mold boxes for anything else you might ever want to cast in case you mix up too much. Once it's mixed, you can't un-mix it so you might as well put it to good use.

 

Step 5, apply a mold release:

No photo here. I considered different options for this. I was going to use petroleum jelly, but I opted to use some craft store mold release instead. You spray it on, brush it with a chip brush, spray it lightly one more time and then let it dry. Using this stuff was a bad idea, as it turns out.

 

Step 6, pour the second half:

Again, no photo. It's just me pouring more purple goo.

Step 7, remove the mold from the mold box:

So, if you look carefully, you will see the issue in the above photo. For those who don't know, the only thing that silicone sticks to is other silicone. The reason for the mold release is to provide a thin film which prevents the adhesion. Here, you can see there is no parting line of any kind. You can see a slight variation in color where I didn't quite have the mix ratio perfect.

 

Step 7a, find a big knife:

Yeah, I had no other way to salvage my 2-part mold other than a big knife. More specifically, I used an old block plane blade which was still sharpened to a shaving-sharp edge. The biggest issue with this is that instead of a nice, clean half-way-up parting line, I will have a jagged, uneven edge. Still better than re-pouring $50 worth of silicone.

 

Step 8, enjoy my handiwork:

Here it is separated in to the two parts. On the left is the "face" of the steering wheel. On the right is the finger-bump back side. The small holes are air holes made by drinking straws with modeling clay in them. You can see how they were placed in Step 7 above. There is also a larger hole for a funnel which is where I will be pouring the resin, eventually.

What's in a wheel? - Part 1

A steering wheel, that is. Well, in the case of my steering wheel, not much. It is a 3-spoke banjo wheel (each spoke is made of 5 thin, shiny stainless rods) with some form of plastic cast over the outer ring. In many wheels, the plastic is cracked and has to be repaired with epoxy putty, sanding, priming and painting. In my case, my wheel looks like this:

You'll notice a distinct lack of plastic. Considering this would have been one of the first plastics used commercially, this is entirely unremarkable. Assuming it was some form of cellulose, it wouldn't be UV, heat or moisture stable. 

So, my options are fairly limited. Option 1 is the sure thing. I could send it out to a professional firm which recasts/restores steering wheels. This option costs between $600 and $2000. Option 2 is that I could look for a wheel from a '38. This was a 1-year part, so I don't like my odds. Option 3 is doing it myself.

I've played around with hobby-scale casting before and it seems doable. The biggest issue is trying to color match the resin. If I fail, I can always paint it, so I'm not too concerned. So, all I need to make this happen is a good condition wheel and some materials and I should be good to go.*

* - Spoiler alert, I alread have a wheel and some materials.

Car Restoration: Misunderestimation

So, a week ago, I posted that I would have some new content in a week or two. Based on my progress, it will probably still be another week or two before I have content. I could write up a set of smaller posts but I'll probably hold back a bit. The delay in my content is a small part typical life delays, but, for the most part, it is due to waiting for shipping. A large part of the amateur car restoration "business" is waiting. You don't know exactly what you need so you start something, find that you are missing something, then order that something and wait for it to show up.

As a small reveal, what I am working on is recasting my steering wheel in new plastic. The basic process is as follows: 1. Get a good steering wheel; 2. Make a 2-part silicone mold of the good wheel; 3. Clean any old plastic and rust off the old wheel; 3. Cast new 2-part color-matched urethane; 4. Clean up the flashing, fill voids and buff/polish.

So far, I've done step 1. I ordered the material for making the mold and casting. I only ordered just enough silicone for the mold, based on the site's estimator because silicone is expensive. I only ordered half as much urethane because I figured I would make a few small samples and trial runs and then order exactly how much I would need once I built confidence that the results would be good. Well, turns out that the estimator for how much silicone I would need was way, way off. I mixed up about half the silicone and poured it, only to find that I needed to mix up almost the rest of what I had ordered to finish the first half of the mold. So, I ordered another batch so I can pour the other half of the mold. Since I didn't want to have to wait again, I also ordered more urethane, which will hopefully be enough to pour the whole shebang. Otherwise, there will be more waiting.

So, my plan is to pour the other half of the mold this weekend and then try a test piece to see if I can get a good color match by eye. If that works, I'll mix up a whole batch of urethane and pour it and see what happens. Wish me luck.

Car Restoration: I Shall Overcome

When you read a car restoration journal on the internet, it presents either a terrible misrepresentation of apparent facts (short, frequent posts of nothing but success and impossible accomplishment in a small time window) or an indication of an owner who is retired and independently wealthy and is always sending things out to be restored. A third scenario happens where someone is a professional car restorer with all the right tools and equipment and skills. And then there are the "others." Most often, you come upon a car blog which is informative and well-written. The blogger starts with some barn find, begins to tear into it, and then disappears from the face of the earth. If you read between the lines, you can see that the car either becomes more than the amateur restorer can handle or becomes too expensive or they just lose focus for years until their wife tells them to get rid of the junk car. At face value, I would appear to be one of the last kind.

In my case, I am a textbook example of someone who probably shouldn't take on a full restoration. When I started, I had no kids and a two-income household. Now, I have 3 kids, no money and even less time. However, I have a sentimental connection to the car, so I am determined to finish the restoration. Now that my youngest is 3 years old, I can start to see a time in the not-too-distant-future where I can have time and money to work on the car. So, recently, I have started to make small but forward progress towards the far-off, eventual completion of the car. In the next week or two, I should have some actual updates for what I have been doing in the last week or so. Stay tuned.