to blast or not to blast........

oligee7275 · Post by **oligee7275** » Thu Feb 05, 2009 4:21 pm

Hi Sylvia,
Since you are restoring the whole bike I say, Yes.
Use glass bead. I have a friend that works in a shop that uses glass bead and I would get used media from him. It works great on our engines. Not too aggressive but will still do the job.
When I couldn't get used media from him I took new glass bead media and put it in the blaster and ran all of it through against a piece of steel first to take the edge off of the media and then used it on my engines.
It will work quickly but still be gentle on the engine alloy.
Dean

schrader7032 · Post by **schrader7032** » Thu Feb 05, 2009 5:19 pm

I was a little concerned about using glass beads after reading other posts by several people. I basically made the decision NOT to use glass beads for blasting when it came to my R69S restoration.

That said, I took my entire engine to the mechanic who was going to do the slinger cleaning and bottom end refurb. He was also going to do my heads which needed valves, guides, and seats. He ended up bead blasting my heads...I sort of felt OK with that as they were fairly contained items and probably easy to clean up.

But I decided to clean the case using elbow grease. Even with it completely empty I felt uncertain about being able to get it completely bead-free.

So, while he was working on the crankshaft, I went to a local car wash and plunked down some quarters and blasted the heck out of the case. I also used a foaming engine degreaser I got at Wally World, along with tooth brushes and the green scotch brite pads. After plenty of quarters and bouts of sudsy spray and clean rinses, I got the case just about as good as I could. It wasn't not too far off what how the heads turned out...which were excellent.

So, I did it both ways...heads got bead blasted, but the engine case was done with elbow grease. It wasn't that difficult doing it at the car wash and I have the satisfaction knowing that there are no glass beads in the engine...OK, maybe there's a couple floating around from the heads, but the likely hood of that is pretty small.

Kurt in S.A.

tricyclerob · Post by **tricyclerob** » Sun Feb 08, 2009 1:42 am

Sylvia,
What I don't like about glass beading is it alters the surface texture of the metal,. It becomes rougher, and seems to open the "pores". It removes the smooth texture and it ends up with a fine sandpaper feel. It takes a considerable amount of work to smooth this up, and I'm not sure you ever get the original smoothness back. Although you end up with a clean, almost white surface, the problem [to me] is it seems every little fingerprint leaves a smudge.
In addition, to me there is considerable danger in not getting all the glass dust, etc.. out of the cases.
What I have used is plastic media blasting. It cleans the surfaces quite well and does not alter the surface texture of the metal. The cases will not quite have that almost white look of bead blasting, but they will be quite clean. They will have a slightly grayer look .
I then finish up with my favorite brand of aluminum polish. It gives the cases,[ to me anyway], a very nice, bright, clean, original looking patina, with out the danger of not being able to clean all the glass dust from the cases.
I've used this on engine cases, hubs, etc.. and have been very satisfied with the results.
Just my 2 cents.

tebogue · Post by **tebogue** » Sun Feb 08, 2009 10:17 am

My first car (in 1964) was a 1930 Model A Ford. Sears had a Model A Ford catalog. All the parts were reproductions. A true restoration uses parts from the period of manufacture. Where the goal is to restore the vehicle to original condition - showroom condition, no better, no worse. Tim

tricyclerob · Post by **tricyclerob** » Wed Feb 18, 2009 12:44 am

Sylvia,
Please don't leave us hanging, what did you decide and how did it go? rj

jimstravlinx · Post by **jimstravlinx** » Thu Feb 19, 2009 8:31 am

still deciding.... i have blasted the heads and cylinders and the front part of the case. ran into a problem with the front main bearing holder being broken so that has taken all my time lately. in the mean time i have the main case in the parts washer and i keep scrubbing it in hopes it will somehow look new.... will keep you all posted... jim

VBMWMO · Post by **VBMWMO** » Mon Feb 15, 2010 2:52 pm

i have been receiving mixed signals on bead blasting the engine cases during a total restoration. presently i am doing an R67/3 and would like to bead blast the engine cases while the guts are out of it. would love some feedback on YES or NO. if yes what are the parameters and if no, what else is there to do the big cleaning job of the stained and oxidized outer surface of the engine cases?

Vintage BMW Motorcycle Owners