sen2two

iTrader: (10)

Just picked up a sandblasting cabinet that I will use solely for cleaning housings, plates, rotors, ect. Mainly the pain in the *** parts of the motor to clean. I am looking at walnut shells Vs. glass bead for my media choice.

Anyone have experience in this? What works the best?

Gurew

iTrader: (4)

good old baking soda is all i would use...and its all i DO use...

C. Ludwig

iTrader: (27)

Soda is the best for engine parts. Allows you to rinse the parts after you blast them to ensure that you get all the media out. Anything else and you WILL have junk left over regardless of how hard you try to get it out.

Gurew

iTrader: (4)

be sure to use high compressed air to blow dry the parts after you rinse them off...else you will have some "flash" rusting on the steel parts...

sen2two

iTrader: (10)

Are there different grades of soda, or are they all the same?

Gurew

iTrader: (4)

there are different brands and grits...the harborfreight media sucks imo...i get my media from grainger...just try the different ones until you find the one you like...

bumpstart

this is very interesting guys -
would anyone be so accommodating to demonstrate some pics of the results
on the plates and manifolds and housings of the various media?

what are all the available options and who has tried what?

do you do something different for finishing the alloy part to the steel ones?

and what are the air volumes and pressures and equipment you are getting some results with?


--- i think all of us rotor owners/builders that are in the remoter parts of the world would very much appreciate some good know-how cause sometimes these services can be very elusive or exclusive

thanks for any replies

Gurew

iTrader: (4)

i use whatever baking soda i can get my hands on..some bags are better than others...generally its dry here in az but when its raining...the soda is a pain to use because of the humidity...

also place an air dryer and regulator just before the blast cabinet...i run 90psi to the gun and make sure the incoming air is oil and water free to get the most "use" out of your media...

i dont change media for iron/aluminum parts...it leaves a very nice clean finish that orings seal just fine on...

Bitchn7

I do soda blasting and have cleaned many engine internals, both piston and rotary (cleaned plenty for my brother, CBR) doesnt hurt anything and cleans off well, hot water best and blow dry straight away. Just dont bother washing them until you need to though, as in the meant time the soda will be best left on to help prevent rusting, otherwise wash them off and treat them as you usualy would.

Aaron Cake

iTrader: (1)

Only annoying thing about soda is it doesn't remove much in the way of corrosion. The latest engine I am building, I blasted with glass beads after thoroughly masking the surfaces. The end result on the aluminum was a nice rough surface which the paint loved. On the steel, it was a perfectly clean surface without any of the corrosion.

Just after cleaning, make sure to CLEAN thoroughly. Blast air through all the passages, then submerge everything in soap and water and again blast anything remaining out with air.

bumpstart

thanks for the replys guys
i think arron just touched on what i was going to ask next
what do you do to protect the sides of the housings if anything?
can this be used to clean water galleries ? or is this a risk to the sealing faces?

more answers, more pics,, help a guy out with blunt fingers from hand rubbing housings and manifolds

bumpstart

PS
what size grits or glass beads and at what application pressures
what airflows does the compressors need ?
( i have a 12 and a 14 CFM compressor tied into one another , each with its own drier, is this enough for a small unit and do i need to booth if using soda )

just startn

iTrader: (33)

I use soda for more mild things, like arron stated. As it gets humid soda just gets aggravating. For the Cabinet i use Black diamond sand, this is what i use on manifolds, housings ect. It leaves a nice texture that paint loves. For the big sand blaster that you use outdoors i just use regular play sand. There are diff grits but i mainly use only one grade grit for the cabinet as it works for wide range of things. I run the cabinet around 90 PSI. anything over that it blows to little sand, anything under that hell you can do better blowing sand threw a straw. I run a 180Gal, commpressor. My blasting cabinet is Home made and the ID of it is 41/2ft deep x 5ft wide. I will Get the number grit i use and pics of the cabinet.

Gurew

iTrader: (4)

be careful using regular sands...as they are used they turn into silica dust which is extremely harmful to breathe and can cause serious lung issues

RotaryEvolution

iTrader: (30)

avoid glass bead for any engine parts that will see the oil system, regardless of how well you clean them.

for example i had an engine come from mazda recyclers in cali that their builder(at that time) used glass bead to clean ALL the engine parts, which found it's way to the oil pan and virtually destroyed a new engine(it had 0 miles on it when the customer brought it to me for diagnosis of hard starting, the engine did sit for 2 years before he bought it so they refused to acknowledge any warranty). the irons were far too pitted also which resulted in very high oil consumption(2 quarts in 50 miles), oil consumption was reduced but still rather high even after i replaced the shitty, worn, blasted oil seal carriers.. all the bearings had to be replaced as one rotor bearing had already spun on a motor that virtually only saw about 5 hours of idling time.

Gurew

iTrader: (4)

which is the reason why soda is the best easy clean up...

dont blast on the area where coolant seals sit on the aluminum housings, try not to spray the chrome

irons..i stay away from the sealing area on the oil pump, stay away from the insides where the oil for bearings reside

do not blast rotors or the eshaft, stationary gears. dont get inside where the bearing resides or on the teeth themselves..just the back portions where the bolts go.

wash thoroughly....what i do is rinse them in water, then wash them with simple green in the parts washer, then rinse again, air dry when you are done with a blow gun/compressed air...

be sure that you 100% clean out threaded bolt holes esp on the front iron where the tension bolts go...you will be 1 pissed off ************ when you have the engine stacked and cant get the tension bolts to thread into your gritty hole same goes for the stationary gear holes in the front/rear irons...so basically...pay alot of attention to the oil areas and threaded bolt holes when you are cleaning the soda out

RotaryEvolution

iTrader: (30)

i wouldn't suggest cleaning the rotor housings with any media at all(except maybe the exterior if you mask off the rest).

the passages should have already developed a corrosion resistant coating in the passages, if you blast them to raw aluminum they can be more easily affected by electrolysis around the spark plugs and exhaust ports from the heat causing a chemical reaction around those areas as it boils the coolant. the coolant seal surfaces can be cleaned with a sanding block evenly sanding around the face, using media will take material off the face and cause the rotor housing thickness to vary, resulting in spots where combustion can get through the housing to iron seal and work at the coolant seals directly.

cleaning the seal surface with media also dislodges minerals that actually allowed the coolant seals to seal against, there is usually alot of minerals in this area so removing them causes large pits to develop which then need to be filled in again. just remember, the seal surfaces don't need to look like new to function like new.

the best way to clean these engines is with your arms, a brass brush and some cleaner(carb cleaner actually works best but is more costly).

D Walker

iTrader: (1)

I would also not use glass beads for aluminum intake manifold plenums or similar that see airflow that enters the engine. The glass beads will lodge in the aluminum and come out later, usually at a very very bad time. The diabilical thing is that the bead particals clump together with fuel/oil in the engine and form an abrasive paste that just destroys everything in its place.

Gurew

iTrader: (4)

correct -^ anything on the sides of the housings..should be touched with the exception of the emissions are where carbon builds up...blasting housings is mainly to clean up the outsides that will be visible for either painting or leaving alone...

just startn

iTrader: (33)

I HOPE anyone that has been reading this thread or following dose not blast there rotors, inside the housings, or the faces of the irons. Basically anything past the outter edges. I would think thats common scence. take a Look at Aaron's cosmo restoration. theres a video of how everything should be masked off

just startn

iTrader: (33)

I have exatly $56 into the whole thing. It works amazing. i just sandblasted a few parts today actually. i made the gloves so your ARMS can go all the way to the back wall.

In it is black diamond 80Grit i believe, its hard to read the bag but im pretty positive thats what is in it.

bumpstart

myself have always used the wire wheel on outside of housings to prep them for 2K paint
and to protect them on the edges i use a couple of dead housings on dowels on either side

RotaryEvolution

iTrader: (30)

yep, i just try to avoid blasting parts altogether. it's more time consuming making sure there is nothing left afterwards than just getting out a wire brush and using elbow grease. if anything i think that baking soda is safest, but also the least efficient.

Aaron Cake

iTrader: (1)

Let me clarify: when I was referring to glass beads, I was referring to the external surfaces only. I'd never blast any of the internal surfaces with glass beads, which includes the water jackets. There would be far too much masking involved to be safe when working so close to machined surfaces.

I've never blasted with soda but have seen others do it on everything from sheet metal to machined surfaces with no real damage to the material being blasted. Seems like it would do the job to clean up the water jackets but in my experience, almost all of that stuff comes out through regular old cleaning. Stubborn deposits just take a little wire brush work and any staining is just, well, staining.

You can see how I masked my stuff for glass bead blasting in part 8 of my Cosmo restoration:

http://www.youtube.com/watch?v=v-0Yl_Jlx1w

In truth, I overmasked quite a bit but this was my first time blasting housings/irons and I didn't want to damage them. Just a single layer of duct tape would have done the job and cut the masking time in half, at least. But I was able to use the same mask for blasting as well as painting, so that saved a bit of time there. After the paint was cured I blew out every passage with soap and water and then brake cleaner. Actually very little media got through the masking. None into the rotor housings, and only a tea-spoon of grit into the front cover area of the front iron. Things like the water pump housing I didn't care much about getting junk into since it can easily be blown out.


12CFM will be fine, but it does depend a little on the type of blaster you use. A pressure blaster will use far less air than a siphon blaster. Blast cabinets are siphon blasters, while a pressure blaster is generally used outdoors or in a blasting room. If you have not purchased a blaster and are just looking for something for around the shop, and you lack a spare room in which to blast, pick up a blast cabinet. I just recently picked up an old blast cabinet and will combine it with my pressure blaster so I can avoid having to tent half my shop when I blast stuff. Media can also be reused many times, which is difficult to do when using a pressure blaster outside. Most blasters like around 90 PSI. My compressor is only rated at something like 7CFM at 90 PSI and it blasts fine.

It's funny you should mention that because a year ago, I was helping someone build an engine. The stuff was powder coated, so it was previously blasted. He did a good job cleaning it out, except I guess the tension bolt holes. Each one was turned tight with a sickening "grind...crush....grind...squeak" noise. It was my suggestion that we pull it apart again and clean the holes but he just wanted it together...Yikes!

just startn

iTrader: (33)

Aaron- how fast does your pressure blaster go threw a single 50lb bag of sand?