The before and after photo......
The Lightening Rocket had a rough life before it wound up in my possession. For me it's a fine line for knowing when to leave "as is" and when to restore. A bike will only be factory original once and I don't want to be the one who messed that up by attempting to make a good bike perfect. So where did the lightning rocket fit in?
No need to worry about ruining an original work here.
My '74 Norton Commando & '70 BSA Lightning are good examples of bikes I don't want to mess with . Both are pretty close to original and perfectly functional. Although not show bikes they are in satisfactory condition. The longer I own and rack up miles on them the more they stray from that condition but I don't see myself restoring either one any time soon. The '64 Lightning Rocket on the other hand needed a serious intervention to be roadworthy. Every time I venture into a different assembly I find another reason for it to have been taken off the road; Fuel taps sealed shut with gasket sealer, the chain setup to short plowing the rear tire into the fender, the carb slide stops cranked into the slides seizing them in place, and a primary chain stretched beyond its useful life to name a few. I should not have expected an easy go of the aluminum part restoration as they were in similar shape. So here it goes....
A mixed lot, some in decent shape and some not so good.
Blasted clean and ready to polish.
Blasted clean and ready to polish.
All of the aluminum parts were broken down to their basic elements and de-greased in a hot soapy bath. The cases required a go with the power washer and engine cleaner. All parts that needed polishing were soda blasted to clean the areas that would be left with their original finish, such as the screw pockets. The main cases were corroded in spots and walnut blasting was used to get them back to their original finish. I prefer walnut and soda blasting mediums as they do not remove much metal in the process. This brings the finish close to that which left the factory. Similar results can be obtained with glass beads under low pressure but any remaining grit from this method will score moving parts.Soda and walnuts wash off easily which avoids this potential issue altogether. I have tried chemical cleaners with limited results and usually give them a go first. They will work if the metal is not corroded, marked or stained to bad. I have seen great results with vapor blasting and it is on my list to try next time.
My Harbor Freight cabinet and craftsman vacuum. A nice setup for the hobbyist.
The valve cover was in fairly decent shape although there was a gouge by the left rear mounting bolt and I am not sure how it got there. It was ground out and worked in with a rotary tool. This spot is hidden by the fuel tap and not easily seen although it came out well anyway.
This would have been a quick job if not for the gouges.
The cover came out well....another boogered part saved.
The largest challenge was the primary cover. A dent left by a foot peg transgression is a common occurrence on BSA's. Fortunately they can be removed as long as the aluminum is not cracked. I start the process by placing the panel on a sand bag and heating the offending area with a MAP gas torch. A ball peen hammer is used to tap and rub out the dent from the inside.
A sizable dent....I have been down this road before.....
The dent removed and on to removing the gouge.
The gouge created when the dent was formed was worked out via a right angle grinder with care being taken to keep everything as flat as possible. Grinder marks are hard to work out...lets keep them shallow.
Grinding marks removed and the cover being blocked to finish prior to buffing. A new dent is identified on the opposite end and will also be removed.
Polishing aluminum is a tedious process if you want to keep surfaces as flat and smooth as they left the factory. I start out with 220 grit to take out gouges and sand to 1200 grit working 90 degrees to the previous direction with each grit. Once a true 1200 grit finish is achieved it's on to the buffer. I start with brown rouge to remove sanding scratches, move to green & then white. Blue compound is used for color matching (Zephyr polishing compounds). A final cleaning is given to all parts and they are buffed with "Mothers Billet". If sanding scratches are found in the final stages a regression in the process is necessary to get them out. Over buffing causes "orange peeling" It's a bit of a balance.
The timing cover prior to air grinding. A bit buggered. A blackened surface aids grinding.
Blocking to prep parts for the buffer. Tedious but necessary for a flat, show finish. Caution....sanding can uncover pits in the casting.....don't take off more than necessary.
Parts sanded to 1200 grit and heading to the buffer.
My new buffer....each grit has its own wheel.
I find this key to getting a show quality finish.
I am very pleased with the final results. Working parts to a high level takes significant time and patience. I could never make any money doing this & it's a good thing I work for myself.
Finished....off of the buffer and onto the shelf until the rest of the build catches up.
My Norton, Triumph, & BSA "riders" ready to go as soon as the Coronavirus stay at home orders expire here in Michigan. This is the summer of doing miles.....
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