Tony's 1954 BSA M21 - The Big 600 
Step Six: Whoops! |
|
|
 |
All that nice paint
Remember (ages ago) when I mentioned that I should have looked closer before I sandblasted and painted the head? Well this is where I found out. Have a look at the photo on the left. Somehow I hadn't noticed the twelve broken fins on the head. They look really tacky and would spoil the restoration. Let's fix them. First we need to - you guessed it - take the head off and sandblast away all that nice new paint.
|
|
|
 |
Making the fins.
Under the guidance of a friend, Bruce, I learned how to do this repair. Note this is a cast iron head and the job should be done only if you are an expert (like Bruce). Using a donor barrel - an old cracked Bantam barrel - we cut the cast iron fins into exact shapes to fit the missing pieces on my head. This is time consuming and detailed work. It must be exact.
|
|
|
 |
Welding the fins
Bruce then carefully welded each fin to its place on the head. The amount of heat used here is critical - too much and the head will warp.
|
|
|
 |
Almost finished
The head with all the new fins brazed on. I have sandblasted the head again and started work with the dremel (see the front fins) smoothing down the weld. When I finish the weld is flush with the fins and I paint the head again with high temperature enamel. Note that we were able to copy the fin profiles from another head so the repaired fins are an accurate shape.
|
|
|
PREVIOUS PAGE |
|