Author Topic: Sandblasting Engine Casings (Read 10900 times)

kidrcth · « **on:** March 04, 2015, 04:06:35 PM »

So last week I brought my engine casings, head and cylinders to a maxhibd shop to clean. Well they did a horrible job to say the least. I can wipe dirt off with my finger still. Yes I paid for it but it was only $40.

Anyways, I started glass blasting and have gotten decent at it. What should I cover before blasting it. Obviously crank journals and gasket mating surfaces. Anything else?

What exactly are the dangers? I feel pretty confident I can get it done.

flybox1 · « **Reply #1 on:** March 04, 2015, 04:12:07 PM »

IIWM, instead of taping the halves, id put the cases together and tape off the remaining exposed areas.
then run it in the parts washer/pressure washer/dish washer to be sure to get all the bead out.
any bead in the tiny oiling holes and your top end will be fooked.

many opt for soda as the blasting medium, because it dissolves in a wash. bead does not.

kidrcth · « **Reply #2 on:** March 04, 2015, 04:22:20 PM »

I did marry them together I was just unsure if that was the best way. I like the dish washer idea. Just wait till the woman is at work. She'll never know.

What tape should I use? Blue masking or duct?

Dino · « **Reply #3 on:** March 04, 2015, 04:26:51 PM »

In my experienced opinion, you should NEVER glass bead or sand blast ANY engine cases. The risk of getting anything in the oil galleries is just not worth it. Just a small amount of the blast media can destroy bearings very quickly. I have seen it happen more than once and it isn't pretty. Best way to clean is in a hot tank or degreaser and pressure washer.

bwaller · « **Reply #4 on:** March 04, 2015, 04:28:40 PM »

I use duct tape, but whatever keep the bead away. Tape all gasket surfaces, openings. Insert bolts or screws into every threaded holes. Don't allow the bead material an entry point. Then afterward expect there might be glass everywhere! Clean, clean, clean after.

kidrcth · « **Reply #5 on:** March 04, 2015, 04:42:38 PM »

The hot tank is what the machine shop did. It did not work.

Whaleman · « **Reply #6 on:** March 04, 2015, 04:48:43 PM »

When I was in the restaurant business (late 70's) I had some cases glass bead blasted. I put each half in the restaurant dishwasher (we were closed) and ran for a half hour. I would shoot out any passageways and change the water and run some more. I remember seeing the glass beads in the water on the dishtable. I did this a few nights after closeing while I was doing the books. Everything came very clean. Dan PS Wife today will allow no parts in the home dishwasher.

kidrcth · « **Reply #7 on:** March 04, 2015, 05:15:55 PM »

I'm leaning toward blasting being my best available idea.

I'll just spend a while taping. And setting it all up.

kidrcth · « **Reply #8 on:** March 05, 2015, 06:04:38 AM »

We have an ultrasonic cleaner for jet engines at work. Think that will clean them up enough post blasting?

chewbacca5000 · « **Reply #9 on:** March 05, 2015, 06:07:00 AM »

Quote from: kidrcth on March 05, 2015, 06:04:38 AM

We have an ultrasonic cleaner for jet engines at work. Think that will clean them up enough post blasting?

Couldn't hurt. Part washer is good too. Why not just plug the exhaust and intake ports and use a siphon feed at low pressure. This way not media can get in the engine at all.

kidrcth · « **Reply #10 on:** March 05, 2015, 06:22:22 AM »

It is my understanding is its hard to keep sand out. Kind of like keeping sand out in a desert. Won't happen. The point of taping is to prevent damage to surfaces.

cgarbe · « **Reply #11 on:** March 05, 2015, 06:30:56 AM »

Great topic! I'm having my engine rebuilt due to a cracked case and am thinking about asking the engine builder to have each individual part (case, cylinder, cylinder head, oil pan, oil filter case, crankcase cover, etc) sandblasted and PC'd before he rebuilds the motor. Any thoughts on recommendations about this?

Bodi · « **Reply #12 on:** March 05, 2015, 06:44:40 AM »

I had my 400 cases blasted many years ago. I put the main case together with sump and side covers on. I don't recall how I covered the top holes but the studs were still on. The head (stripped of valvegear) and rocker cover were separate.
They came back clean but glass everywhere.
I took them to a coin op car wash (I didn't have a pressure washer). I quickly learned I needed protection, the spray bounces back from holes and case curves right back at you. I put on my rainsuit and a scuba mask and really went at the cases. It took a lot of coins, but they came out with no grit I could find. I did chase all the threaded holes with a bottoming tap and washed the cases at home in a tub using Tide and hot water, then rinsed with a garden hose (I saw a video about a NASCAR engine builder and they cleaned parts with Tide - sure Tide is a NASCAR sponsor and maybe that was just for the video... but if it's good enough for NASCAR it's good enough for me).
I haven't seen any damage, I've been into the engine twice since and the bearings look good, clearances have crept up but are still within spec.
The last washing was to remove any grease or oil from handling them, I also did an acetone wipe before treating the head, cylinder fins, and all case outsides with black Gunkote: wife was not happy with the (nasty) stink when I baked them in the kitchen, but that coating is still looking good 20+ years later. Except a shop reblasted the cylinders and head - not asked to - about 10 years ago so the motor is a bit odd looking now. I would Gunkote them again but they no longer sell rattlecans of it.

kidrcth · « **Reply #13 on:** March 05, 2015, 06:53:22 AM »

I sand blasted all of the parts to the engine except cylinder, head and cases in my driveway. Costed $25 total and was super easy. There is a learning curve but was easy to figure out a technique. Everything came super clean.

Blaster was $15 at HF
50# bag of Glass was $9.99 at northern tool

Super easy

DaveBarbier · « **Reply #14 on:** March 05, 2015, 08:59:22 AM »

I had my engine blasted too. I think he used some calcium something or other. Heavily taped up holes with black duct tape but there was still a lot in the motor. Just washed everything many times over and it seemed fine.

---
1978 Honda CB550K

edwardmorris · « **Reply #15 on:** March 05, 2015, 09:14:37 AM »

Gordon's advice to me when I got mine done.

http://forums.sohc4.net/index.php?topic=126735.msg1506906#msg1506906

I followed it all except the gasoline dunk..

Quote from: Ilbikes on February 08, 2014, 06:08:30 AM

Hi Ed, Gordon here. I've had dozens of cases, heads, and cylinders beadblasted over the years. You have to visualize that the blast material is sandpaper inside your engine. You have to get it out. I have a large plastic storage bin that will hold a crankcase.

I start off with a very high-pressure nozzle and wearing safety goggles, I blow into every hole, crack, and corner. Do not run the tap through the holes unless you have a damaged one - the tap removes tread material. Make sure every threaded hole is clean.

I then soak the casting in solvent (I use gasoline outside, but it's not proper nor safe) and I rock the bin side to side, soak some more, rock, soak, rock - until every piece is what I think is pure metal. I then remove it and blow with high-pressure again.

Lastly, I fill that same bin with hot-soapy water. I mean I get buckets of hot water out of the tub faucet and Dawn dish washing soap and soak/aggitate those castings again and again. I then take them to an outside drain and lay them on the bin's lid and run my garden hose over them and then blow again with the high pressure. I let them dry and and only then do I feel they are ready for assembly.

Please note that even after all this cleaning, the first oil change is something I do at 100 miles. There will still be some media in the filter.

Best Regards, Gordon

kidrcth · « **Reply #16 on:** March 05, 2015, 09:36:22 AM »

yeah I shall do the same minus the solvent soak

kidrcth · « **Reply #17 on:** March 05, 2015, 10:15:09 AM »

what about using walnut shell?

flybox1 · « **Reply #18 on:** March 05, 2015, 10:19:39 AM »

im sure it'd work, but no matter what is used, the emphasis is on oil passage clean-out.

Powderman · « **Reply #19 on:** March 05, 2015, 10:53:06 AM »

Mask with blue painters tape and then go over that with duct tape. The painters tape will get eaten up by the blasting but the duct tape won't. The duct tape will have the adhesive beaten into the surface making cleaning a necessity afterwards. The Blue tape won't leave residue if it's blasted under the duct tape.

kidrcth · « **Reply #20 on:** March 05, 2015, 11:00:09 AM »

After going out and surveying what was done it frustrated me even more that the machine shop, that prides itself on clean, did such a poor job.

Garage_guy_chris · « **Reply #21 on:** March 05, 2015, 12:23:34 PM »

I have a couple things to add, to block off ports and other "bad" areas expanding winterizing pool plugs work well and can be bought at the local pool shop for a couple bucks.

As for other masking duct tape on bearing saddles masking tape on gasket surfaces, often i will go over these plugs with tape too...

Also when i clean the cases after blasting i fill the laundry sink with the hottest water i can get out of the faucet then add a bunch of dish soap and let them soak for a while in the hot water, it helps to get any grease or oil out of the metal or any places. after a good soak i put a 2' garden hose end on the tap and blow hot water through all the oil galleries in every direction possible and i do this with every block off, plug or fitting out of the system. it doesnt take much sand to take out plain bearings

DaveBarbier · « **Reply #22 on:** March 05, 2015, 12:58:51 PM »

Quote from: Powderman on March 05, 2015, 10:53:06 AM

Mask with blue painters tape and then go over that with duct tape. The painters tape will get eaten up by the blasting but the duct tape won't. The duct tape will have the adhesive beaten into the surface making cleaning a necessity afterwards. The Blue tape won't leave residue if it's blasted under the duct tape.

Must depend on how careful the blaster is. My 3 layers of duct tape got shredded apart.

---
1978 Honda CB550K

kidrcth · « **Reply #23 on:** March 05, 2015, 01:31:05 PM »

i gave up on the case assemblies. I called a friend who does custom motorcycle work, he gave me the number for a guy that does custom motorcycle engine builds. I took it to him and he said he could clean them up for $50. We shall see. I hope he is right. Otherwise my buddy said there is a company that will take them and clean them for $100, but i would have to send them out. NBD. I just dont want to ruin my engine because of lack of cleaning or masking.

I sand blasted the head and cylinder just now tho. Was a lot easier to do those, not as much to worry about afterwards. Now i need to clean out the dish washer

markb · « **Reply #24 on:** March 05, 2015, 03:48:03 PM »

I actually think the cases are easier to blast than the head and cylinders. But whether you do them or someone else does them the cleaning part is the same. I wouldn't trust anyone to get everything clean enough. I like the car wash and compressed air method. Messy at the car wash though. I lay the parts on a piece of plywood. If everything is degreased well that helps prevent sand from sticking anywhere. After I think it's clean enough I clean it a couple more times. I do the 100 mile (or less) oil change that was mentioned too. Two engines, no issues. Good luck.

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Author Topic: Sandblasting Engine Casings (Read 10900 times)