Muckroot
XS650 Addict
Hello all,
I have a 1975 XS-B that I am rebuilding, but unfortunately the case was unusable. Gary Hoos from Hoos racing (http://www.hoosracing.com) sent me a XS-J case for the cost of shipping. An absolute saint, I must say. Anyway, I decided to try and remove the black case paint from the XS-J case because I wanted to retain the classic bare aluminum look of the 1975 XS-B engine.
First I tried Aircraft chemical paint stripper, and while it did technically work it was slow, relatively expensive, and completely failed to strip 100% of the paint from the places a brass brush couldn't reach. So I decided to try soda blasting, because I had heard about it once on some completely unrelated forum (I think it was regarding removing gun finishes idk). I followed a 3 minute youtube video on how to make a sandblasting attachment for an air compressor, spent a whopping 10 dollars on parts: 7$ for the attachment components at harbor freight and 5 boxes of baking soda from the dollar store.
I first tested the setup at 80 PSI on the old broken case to see if the blasting would ruin the gasket surfaces. I blasted the case-to-jug surface for a solid minute with direct spray and found that it had removed all the gunk, patina, and old gasket from the surface of the case without touching the aluminum itself. this seemed way too good to be true so I sacrificed the brand new polish on one of the rocker covers I did yesterday to see if the soda blasting would affect the polish noticeably. I figured even if it stripped the polish I could just rebuff the cover and it'd look good as new.
Long story short, the soda blasting at 80PSI does in fact microscopically pit the surface of the aluminum. it will remove the polish from buffed aluminum. BUT: this pitting (in my opinion) is so finite that it is not a factor in gasket seal integrity, and I'm willing to bet if gasket sealer paste is applied along with fresh gaskets on a soda blasted gasket surface it'll work better than the stock milled gasket surface. I fully intend to keep you guys updated in the long run and let you know if this engine produces leaks at high mileage due to this soda blasting process. I decided to intentionally soda blast the gasket surfaces on the case to get the most definitive results possible. Worst comes to worst I can always tear the engine apart and polish all the gasket surfaces with a Dremel and some Mother's mag and aluminum polish.
I settled on blasting 0-1 inches from the surface at 70PSI, both at oblique angles and straight on. crater shadow was a bit of a bummer, but not unmanageable. This is my second time blasting something.
Anyway, this is how far I got today, as well as how the soda blasted surface compares to the old non-painted case.
And before anyone asks: Yes, I did use the proper PPE for this. the bandana was just for the initial test. I switched to a proper particle respirator and Saftey glasses when I started going to town on the XS-J case. Also, my mouth tasted like baking soda, so that was a bummer lol. I am happy to field questions.
I have a 1975 XS-B that I am rebuilding, but unfortunately the case was unusable. Gary Hoos from Hoos racing (http://www.hoosracing.com) sent me a XS-J case for the cost of shipping. An absolute saint, I must say. Anyway, I decided to try and remove the black case paint from the XS-J case because I wanted to retain the classic bare aluminum look of the 1975 XS-B engine.
First I tried Aircraft chemical paint stripper, and while it did technically work it was slow, relatively expensive, and completely failed to strip 100% of the paint from the places a brass brush couldn't reach. So I decided to try soda blasting, because I had heard about it once on some completely unrelated forum (I think it was regarding removing gun finishes idk). I followed a 3 minute youtube video on how to make a sandblasting attachment for an air compressor, spent a whopping 10 dollars on parts: 7$ for the attachment components at harbor freight and 5 boxes of baking soda from the dollar store.
I first tested the setup at 80 PSI on the old broken case to see if the blasting would ruin the gasket surfaces. I blasted the case-to-jug surface for a solid minute with direct spray and found that it had removed all the gunk, patina, and old gasket from the surface of the case without touching the aluminum itself. this seemed way too good to be true so I sacrificed the brand new polish on one of the rocker covers I did yesterday to see if the soda blasting would affect the polish noticeably. I figured even if it stripped the polish I could just rebuff the cover and it'd look good as new.
Long story short, the soda blasting at 80PSI does in fact microscopically pit the surface of the aluminum. it will remove the polish from buffed aluminum. BUT: this pitting (in my opinion) is so finite that it is not a factor in gasket seal integrity, and I'm willing to bet if gasket sealer paste is applied along with fresh gaskets on a soda blasted gasket surface it'll work better than the stock milled gasket surface. I fully intend to keep you guys updated in the long run and let you know if this engine produces leaks at high mileage due to this soda blasting process. I decided to intentionally soda blast the gasket surfaces on the case to get the most definitive results possible. Worst comes to worst I can always tear the engine apart and polish all the gasket surfaces with a Dremel and some Mother's mag and aluminum polish.
I settled on blasting 0-1 inches from the surface at 70PSI, both at oblique angles and straight on. crater shadow was a bit of a bummer, but not unmanageable. This is my second time blasting something.
Anyway, this is how far I got today, as well as how the soda blasted surface compares to the old non-painted case.
And before anyone asks: Yes, I did use the proper PPE for this. the bandana was just for the initial test. I switched to a proper particle respirator and Saftey glasses when I started going to town on the XS-J case. Also, my mouth tasted like baking soda, so that was a bummer lol. I am happy to field questions.