Cars


Mini Rebuild

 

Step 38 - Fun with Fiberglass

 

After purchasing a set of wheels for the Mini last August, I decided I should buy one more to serve as the spare. Only one problem - no one makes 5x10 Revolution wheels anymore. I'm still not even sure how I found my set. After lots of searching, I found someone in England willing to sell me a single Revolution wheel he had laying around. It needed some fixing up, but the price was right. Here are the pics he sent:

 

Mini Rebuild Step 38

 

Mini Rebuild Step 38

The pics didn't lie. The wheel looked at least that bad when it arrived. I've heard for years that shops can repair cosmetic flaws in wheels but I'd never seen the results myself. For $100 I thought I'd give it a try, entrusting a shop in San Jose called Wheel Techniques. A week later, here's how it turned out:

 

Mini Rebuild Step 38

I'm pleased. After Five Point Tire mount an Aquatusk on it, my new spare was ready to go.

 

Another small item I took care of was finishing the fiberglass panels I had fabricated.

 

Mini Rebuild Step 38

 

Mini Rebuild Step 38

 

Mini Rebuild Step 38

 

Mini Rebuild Step 38

I've decided to redo the lower dash in the car. More on this later.

 

Mini Rebuild Step 38

Although I installed the new repair panels at the back of the car a couple months back, I wasn't completely finished. I cleaned up rear valence and closed off these holes in the side.

Mini Rebuild Step 38

 

Mini Rebuild Step 38

 

Mini Rebuild Step 38

I also cleaned up these welds around the boot opening.

Mini Rebuild Step 38

 

Mk1 Mini's came with a plastic two-piece cover that covered the steering column and turn signal mechanism. The larger diameter steering column I built meant the stock cover would not work. However, in an effort to retain as much of the original car's look as was possible, I had already decided to use a Mk1 turn signal stalk. Why not use the original column cover as well but modified to fit my car?

 

I used the basic procedure layed out in this thread about making a custom-shaped carbon fibre motorcycle fuel tank. I could have made my column in CF but there is no need to and chose fiberglass instead. This is a non-structural part, will weigh close to nothing even in fiberglass, and won't justify the added expense of cf. I needed to start by building a male mold - essentially a part whose outside shape is identical to what I wanted my final part to be.

 

Mini Rebuild Step 38

These are the stock steering column covers. They taper down to too small a diameter to work with my column but they are the perfect starting point.

 

Mini Rebuild Step 38

I used as much of the original covers as I could and then cut off the rest.

 

Mini Rebuild Step 38

This clear acrylic tubing is just large enough in diameter to fit over my steering column. I'll use it to make the original mold shape.

 

Mini Rebuild Step 38

Here you can see them test-fit to the column. Satisfied that this could work, I glued the tube to the covers with CA gel.

 

Mini Rebuild Step 38

I then used kitty hair (fiberglass-reinforced body filler) to smooth the transition between the parts and make it appear like they were originally designed to be that shape.

Mini Rebuild Step 38

Next I applied glaze filler to smooth everything out and get the final shape.

 

Mini Rebuild Step 38

The glaze was followed by a few coats of grey primer. This highlighted several flaws like pinholes in the filler and poor shaping of the filler. I corrected all of this and re-primered.

 

Mini Rebuild Step 38

 

Mini Rebuild Step 38

 

Mini Rebuild Step 38

 

Mini Rebuild Step 38

Finally the shape looks good. It is symmetrical and transitions nicely between the original shape and the acrylic tube.

 

Mini Rebuild Step 38

Time for the final coats of primer.

Mini Rebuild Step 38

 

Mini Rebuild Step 38

Once I was satisfied it was time to make a female mold of this shape. Because I need the finished steering column cover to be in two pieces, I had to make two molds. First step here was to attach the mold to a section of metal tube. Then I made a cardboard template of the mold's exterior shape.

Mini Rebuild Step 38

 

Mini Rebuild Step 38

I transferred that shape to a piece of fiberboard which I then cut out using a jigsaw.

 

Mini Rebuild Step 38

I cut a hole in a piece of fiberboard then placed the male mold with half of it sticking above the surface of the board.

 

Mini Rebuild Step 38

I used modeling clay to fill in any gaps between the board and mold.

 

Mini Rebuild Step 38

I laid down strips of duct tape around the mold hoping to ensure that the female mold would more readily seperate from that than the wood. I didn't think the fiberglass would easily conform to the mold's contours perfectly so I cut out shapes that I thought would. (In hindsight this was not necessary. The weave style of fiberglass conformed perfectly to the interior of the female mold at the next step of the project).

Mini Rebuild Step 38

I used my paper templates to cut out four layers of fiberglass mat per section. Time consuming and ultimately unnecessary. Oh well.

 

Mini Rebuild Step 38

With everything in place, I polished the primer on the surface of the mold, applied two coats of wax, then sprayed on some mold-release.

 

Mini Rebuild Step 38

I laid down a total of four layers of fiberglass. After allowing it to dry overnight I removed the male mold + one-sided female mold from the fiberboard fixture. As you can see I placed a flange, an additional strip of fiberglass, all around the mold. I felt this would make it easier to work with the female mold later on as well as give it a bit of additional strength. All the black lines are permanent ink lines I drew on the fiberglass mat prior to cutting them out.

 

Mini Rebuild Step 38

Here is the underside of the mold - the half that wasn't protruding above the board. Notice the excess clay that was pushed through the gap to this side. You can also see the tape I applied to prevent any resin from accidently getting on this half of the mold.

 

Mini Rebuild Step 38

Now it was time to make a female mold of the second half of my male mold.

 

Mini Rebuild Step 38

I repeated all the same steps as I did for the first half of the mold.

 

Mini Rebuild Step 38

Once dried, I used the Dremel cutting wheel to trim off the edge of the mold flanges.

 

Mini Rebuild Step 38

I then used some prying tools to pop the female molds off the original.

 

Mini Rebuild Step 38

Some of the primer seperated from the male mold but this was easy enough to sand off of the female mold. Overall I'm please with how they turned out. To prepare them for making the steering column covers I would normally want to get them perfect as any problems in the shape or surface quality of the molds will be tranferred to the final part. However, I only intend to make one set of the steering column covers. I can spend my time making the molds perfect or spend my time more easily correcting the final part. I chose the latter.

 

Mini Rebuild Step 38

I did at least remove the primer stuck to the interior surface of the female molds, then sprayed them with a few coats of grey primer.

 

Mini Rebuild Step 38

I then laid down a strip of low-tack tape around the edge of each mold, again to aid in removeal of the finished part. I applied four layers of fiberglass, one at a time. You'll also notice that I used some black dye in the resin. I wanted the final part to be black, so why not start with black?

 

Mini Rebuild Step 38

 

Here is one side complete after being popped out of the mold. Again some of the primer came with the part instead of staying on the mold.

 

Mini Rebuild Step 38

And after a quick rough trim with a Dremel cutting wheel.

 

Mini Rebuild Step 38

 

Mini Rebuild Step 38

The next step is finding a way to install the covers securely around the steering column. I opted for two fiberglass rings around the interior of the covers. These will provide flat areas to contact and hopefully will allow me to drill out to install some fastening hardware. This photos shows a fiberglass stip prior to installation.

 

Mini Rebuild Step 38

This photos gives you a rough idea of how the inner rings fit into small diameter areas along the steering column.

 

Mini Rebuild Step 38

This last photos shows the built-up layers of fiberglass strips lining the inside of the cover halves. More soon...

 

Continue to Rebuild Step 39

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