Sandblasting my motor

JDman21 · Post by **JDman21** » Sun Mar 18, 2007 12:16 pm

I was thinking on sandblasting my motor to clean it up. Can I do that? If I can should I spray it with something so it doesnt rust?

qwerty · Post by **qwerty** » Sun Mar 18, 2007 1:26 pm

if you are doing a complete rebuild and removeing all moving parts inside the motor. then yes you can but you have to take precautions. first take your crank, oil pump,water pump,gears,etc,far far away.you will have to re assemble the motor and plug all holes and protect all mating surfaces with silicone. indiscriminate use of the blaster will erode parts that you dont want it to, like chrome nuts, carb flanges, seal surfaces. REMEMBER A SINGLE GRAIN OF SAND INSIDE A RUNNING ENGINE WILL DESTROY IT. then you will have to thoroughly wash and repaint it because a freshly blasted aluminum surface will oxidize rapidly. then try to reassemble without scratching your work.
you would be far better off cleaning the complete engine thoroughly by hand. then degreasing with something like laquer thinner and painting the appropriate color.

400brian · Post by **400brian** » Sun Mar 18, 2007 4:41 pm

Don't use sand on aluminum. Blast with walnut shells or a plastic medium, sand will remove metal.

JDman21 · Post by **JDman21** » Sun Mar 18, 2007 4:51 pm

After I blast it what should I spray on it?

Danzig · Post by **Danzig** » Sun Mar 18, 2007 4:55 pm

Personally I would take the block to a engine shop and hot tank it.

400brian · Post by **400brian** » Sun Mar 18, 2007 5:02 pm

Then polish it!

Liquifire 4/6 · Post by **Liquifire 4/6** » Sun Mar 18, 2007 5:51 pm

I'd tend to agree with Danzig that hot tanking it would be the best idea, however I have blasted some engines with good results, but I can not emphasize enough the importance of thoroughly washing it several times before reassembling it. I wouldn't use sand either.......it is overly abrasive and actually does not leave a nice finish on the aluminum anyways...it tends to make it look quite rough. I've done mine with medium size beads. Different size beads will leave totally different finishes on the aluminum. So, experiment a little on a scrapped engine component. Also, be sure to find some old metric bolts that you no longer have use for and screw the used bolts into absolutely every threaded hole before blasting the crankcase or cylinders. If you don't, the beads will distort the internal threads and you may find that you can't thread a bolt into them....or you'll thread it in, but will not be able to tighten it properly...a torque wrench will show you a proper torque reading before the bolt is actually holding the components together properly. I've learned that the hard way. Really, if at all possible, I'd avoid blasting it. It's amazing how well you can clean cases and cylinders with a couple evenings of hand polishing.....fine steel wool works great, and I've used small brass brushes to get into the tiny spots....then after you get it as clean as you can, go at it with some Mother's aluminum polish or similar product. I remember a few years back making an old kawasaki Liquifire shine every bit as well as that engine on page 17 of the 1982 brochure using only hand polishing. Have fun doing it....the finsihed product will be worth the work.

Pete

Mr. Deere · Post by **Mr. Deere** » Sun Mar 18, 2007 6:10 pm

I used WD-40 on my engine along with a scotch brite and it worked fairly well. BOB

BigJohn · Post by **BigJohn** » Mon Mar 19, 2007 7:52 pm

Over the past couple of years, I've used baking soda to blast engines. I doesn't remove the metal and yet it works great! But, I would definetly agree with Danzig and hot tanking it. Simply a failsafe approach to engine work!

Brad

chains1017 · Post by **chains1017** » Tue Mar 20, 2007 8:31 am

Ive used a cleaner called challenge on a few engines. It is acid based, I believe and makes the aluminum perfectly white with some hand cleaning in heavily greased areas. You have got to be careful though as it will etch the aluminum in sometimes not so good ways, if you leave it too long. I usually spray it on let it set and powerwash. Sometimes it takes a couple times, but the outcome is pretty sweet! Ive also used it on chassis , but have achieved mixed results, as sometimes it streaks. Cya Doug

mgabl072 · Post by **mgabl072** » Fri Mar 30, 2007 3:34 pm

Has anyone ever chromed the cylinders?

Liquifire 4/6 · Post by **Liquifire 4/6** » Fri Mar 30, 2007 4:23 pm

Yes, Kawasaki chromed the inside of the bore of all of them. Yeah, I know....I'm being a smart a$$....just couldn't pass it up. I bet they'd look awesome in chrome, but it sounds expensive....and I'm not sure how a chrome finish would affect the heat dissipation characteristics of the cylinders. Maybe it would have no effect at all. Anybody know?

Pete

Mr. Deere · Post by **Mr. Deere** » Fri Mar 30, 2007 5:03 pm

Is this hot tank the same stuff a Car garage would use. I know some one who works at a car dealership and he is a mechanic so he could dip if its the same stuff. Our shops not up at school but i think we might have a tank or just a trough with liquid in it. BOB

mgabl072 · Post by **mgabl072** » Fri Mar 30, 2007 6:55 pm

That is my concern, heat dissipation. Anyone's additional thoughts?

Chroming is not that expensive if you find a auto shop that has a bunch of things to chrome and you sweet talk the guy to throw your items in with the stuff. A $50 bill and a case a beer goes a long way.