Best media to use for an intake manifold?

[Drew Pojedinec]

I know this thread has been dead for a long time.

So I got 50lbs of soda and 50lbs of Garnet in 100grit.

Obviously the soda I had to use outside, it was messy, painful and probably costs $15-$20 an intake to do on account of the media not being reusable.
I still chose to not glass bead, as I've had it get stuck in threads and the like and I just don't trust my ability to clean it.  Maybe if I had some massive washer I would try it, but I have what I have to work with.

The 2x4 intake was done with soda, the 3x2 intake was done with garnet.
The garnet seems to polish the surface a bit more, and I can use it in my cabinet (tho it is slightly dusty compared to glass beads).

IMG_1003 by Drew Pojedinec, on Flickr

IMG_1002 by Drew Pojedinec, on Flickr

IMG_1001 by Drew Pojedinec, on Flickr


I think I'll further my experiments with Garnet.  It does NOT get stuck anywhere that I can see, simple air appears to remove it, water probably more so.  Right out of the blast cabinet I threaded bolts into hole and no evidence of grittiness, etc.  It does make it whiter and less aluminum looking.  I will probably go and find a few different grits to play with.  I like being able to use my cabinet as the work isn't weather dependent. 

Hard to tell from these photos, but the soda did not remove embedded dirt, I had to scrub with a stainless brush and brake cleaner for a long time and reblast and it still left some mottling.

Another garnet bonus is I did a few carb bowls and dichromated them, they came out very nice, tho I lowered the air pressure to 40psi as garnet it "cuttier" than glass beads.  Not having to switch media is a bonus as I just have one cabinet.

Anyway, figured I'd report some findings.

Drew

[Stangman]

They both look good Drew. The color difference I think is normal,I don’t think the aluminum
Intakes are all the same color. I originally sand blasted my intake then power washed the crap out
of it. Then bought clear coat from Eastwood and sprayed it came out sweet.

[Drew Pojedinec]

Hrm, clearcoat might be cool.  I'll have to play with that.

I ended up going and putting the 2x4 in the blast cabinet and hit it with the garnet, it assumed the same appearance as the 3x2.  Either way it's nicer than when I started.  Just waiting on an air cleaner, linkage, fuel log, and a pcv block plate and I can ship it out to Australia.

IMG_0530 by Drew Pojedinec, on Flickr

IMG_0716 by Drew Pojedinec, on Flickr


Either way, just documenting my findings, so maybe someone else might save some time or money experimenting.  I make a little selling carbs, etc so I don't mind buying 4 different media and throwing 3 of them away

[Heo]

I had to check garnet up in the dictionary....MR fancy smancy using
gemstones in his blasting cabinet no cheap glasbeads here


(just pulling your chain Drew )

[Stangman]

Holy crap Drew you got a couple of carbs don’t you, do you have a bunch of 2x4 medium riser intakes

[Drew Pojedinec]

Holy crap Drew you got a couple of carbs don’t you, do you have a bunch of 2x4 medium riser intakes

I wish..... seriously, if I had ten of them right now I could sell them.  Folks are hungry and BT is just like "meh"
As far as a lot of carbs, those are just the generics, I have probably 50 or so 1850-1's at any time.  This year I think I've restored and turned out somewhere between 20-30 sets of 2x4 carbs, probably more, I just haven't bothered counting. 

Heo, Garnet apparently will not embed and fall out later, it really isn't any more expensive than glass beads.  It breaks down faster, so I'll be replacing $80 worth every 4 months instead of every 6months.

[Heo]

I know, probably the most common and cheapest gemstone there is
more like a mineral but sounds fancy .. i use no fake
glas beads, real jewels here.....Ahhhh i should not try to tell a joke
in a strange language

[Falcon67]

Drew's place is where all 1850s go to die and be re-born.

I've glass beaded one intake - like Jay, got all the gook out of the runners first but just blasted away.  Put it in a tub with hot soapy water and scrubbed good, rinse, air dry, do over, blow out - no noted problems.  Runs fine, engine didn't explode.  Should have, I read it on the Internet.

[Drew Pojedinec]

Well Chris, I’m sure you understand my situation. I’m willing to risk stuff on my engine that I wouldn’t dare risk on a customer engine.

Anyway, just documenting findings and maybe helping someone else make an educated decision for their own stuff.
I’m enjoying doing these full “drop in” intake/carb setups.

[chris401]

No aircraft engine manufacturer or authorized rebuilder is allowed to use any glass beads.

An AEC tech bulletin (one I could not copy as a PDF here!):

Title: Dangers of contamination from Glass Bead Material

Technical portions are approved by Airmotive Engineering Corp.
T.N. No.: 09-2
Page: 1 of 2
Issued: 2-10-10
Revision: 0
1.0 PURPOSE: To help prevent engine failures
2.0 SCOPE: To alert technicians and mechanics about the perils related to glass beads
3.0 APPLICATION: Maintenance of aircraft piston engines.
4.0 REFERENCE: Engine Manufacturer’s overhaul manuals and service bulletins, service
instructions and service letters (Continuing Airworthiness Instructions) should always be
consulted as the principal authority for any engine overhaul and maintenance information.
5.0 DISCUSSION: One of the methods used by technicians and mechanics to clean component parts
is to shot blast using glass beads. This procedure has some benefits over other cleaning
procedures, but all of the benefits pale in comparison to the devastation that glass beads cause
when they are introduced in any manner into the inner workings of an aircraft piston engine. Even
one glass bead can cause significant damage before it breaks up into glass dust. If it is trapped in a
bearing it does its damage and then can re-circulate to do some more.
Many shops keep glass bead blast media and only use it to clean external parts. Others believe
that proper cleaning will eliminate the hazard. There are two axioms that should be posted in
every engine shop:
1. If glass beads are any where in any quantity in an aircraft repair facility, they will end up
in aircraft engines!
2. The only thing that loosens up and moves glass bead media from the nooks and crannies
of aircraft engines and into areas where they cause the most harm is hot engine oil!

Most engine overhaulers or repairers have experienced problems related to glass beads. However,
many were never aware of the root cause for their problems, and either gave up on the search for a
cause or attributed the cause to something else. This is because glass beads will defy cleaning
efforts and are difficult to identify after the damage is done. Airmotive Engineering Corp. and
Engine Components, Inc. have experienced the problems caused by glass bead blast media many
times over the years. Because of these experiences (i.e. warranty claims), our technicians have
developed highly effective evaluation techniques, and it is rare that positive evidence of glass
beads cannot be found.
T.N. No. 09-2
Revision 0
Dangers of contamination from Glass Bead Material
Page 2 of 2
 The photograph below shows glass beads that were solvent washed from behind piston rings of
cylinders sent back to ECi for warranty consideration. The pistons, rings, cylinder bores, and
bearings were severely damaged and unserviceable.
Photo 1: Glass Beads in Engine Oil and Solvent

6.0 Conclusion: It is of utmost importance that glass beads not be used in any manner to clean piston
engine parts. Even one glass bead can cause significant damage, and failure to comply with this
instruction will result in denial of a warranty cl

Re: continentalmotors.aero/xPublications/xService%20Bulletins/ECi%20Archives/09-2/

I rest my case that unless one can almost surgically clean, even an intake, from 100% of all glass beads, other media is preferred.

Glad I clicked this link. I used glass beads on my engine parts because I was instructed to use it at work. I cleaned rods and rocker arms in a glass cabinet before shot pin and refinish. Barry's experience in perticular was educational.