Discussing sand blasting odds and ends - Page 2
Close
Login to Your Account
Page 2 of 2 FirstFirst 12
Results 21 to 36 of 36
  1. #21
    Join Date
    Jan 2007
    Location
    Flushing/Flint, Michigan
    Posts
    11,371
    Post Thanks / Like
    Likes (Given)
    692
    Likes (Received)
    9096

    Default

    Quote Originally Posted by EmanuelGoldstein View Post
    I have in Real Life used silicon carbide. A friend who does lots of hard facing on cast iron has two blasters, one with beads and one with carbide. That's a sensible setup.

    The carbide rips away material like nobody's business. Internal splines commonly shrink a bit in heat treat, you can remove enough material carefully with silicon carbide to make them fit again. With beads or sand kiss that idea off, it'd take a week. Silicon carbide makes regular sand look like kids' stuff. As Garwood points out, using it on paint and the like would be a no-no but for ripping slag off cast iron, it kicks ass.

    Here comes thermite out of the woodwork but one thing about it : static electricity. .
    The mix in the blaster matters so much more than nozzles.
    And then pressure which is so often dialed up to high.
    Add the love of pokes through the gloves. What the heck is that?
    It seems so simple and straightforward.
    Bob

  2. #22
    Join Date
    Oct 2005
    Country
    UNITED STATES
    State/Province
    Pennsylvania
    Posts
    23,102
    Post Thanks / Like

    Default

    Quote Originally Posted by CarbideBob View Post
    It seems so simple and straightforward.
    Glass, alumina oxide. silicon carbide percentage and so many grit sizes in the mix and one can go crazy.
    Bob
    Ya forgot walnut hulls, corncobs, cherry pits, and plstic(s).....

  3. #23
    Join Date
    Mar 2019
    Country
    UNITED STATES
    State/Province
    Wisconsin
    Posts
    3,625
    Post Thanks / Like
    Likes (Given)
    176
    Likes (Received)
    1054

    Default

    Lots of great suggestions and info.

    Have processed lots of parts and found that introducing grease and oil into the blast cabinet really fouls up the blasting media.

    Some paints and coating really defy sandblasting much like tape is used to mask surfaces. You almost have to spend time precleaning in order to process dry parts free of as much paint as possible.

    Blasting oily greasy parts usually results in the media getting trapped in threaded and blind holes.

    Many automotive machine shops have been using the 3 step bake-blast-tumble systems for years now, doing away with caustic wash cabinets. You may want to ask around.

    And, have had real good luck with red garnet sand on steel and cast parts. Same stuff the water jet guys use. It flows quite well. Low priced red garnet usually is very dusty, so by the 50# bags that are usually supplied to the water jet guys. Don't try to salvage used water jet sand.

  4. #24
    Join Date
    Apr 2018
    Country
    UNITED STATES MINOR OUTLYING ISLANDS
    Posts
    10,386
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    5011

    Default

    Quote Originally Posted by CarbideBob View Post
    Add the love of pokes through the gloves. What the heck is that?
    A byproduct, I think. Small parts, you hold in your hand and blast. Blast hits the parts, also hits the gloves. 200 parts later = hole in glove. Cheap bastard (me) tries to hold in a different place to avoid beadblasting hands, with limited success.

    Smooth skin tho

    Kinda like working with batteries for a week, when ya gotta job lined up. No prints.

  5. #25
    Join Date
    Oct 2009
    Location
    Oregon
    Posts
    6,777
    Post Thanks / Like
    Likes (Given)
    7262
    Likes (Received)
    4102

    Default

    Quote Originally Posted by GregSY View Post
    It's not an issue of being an asshole...it's an issue of life in 2021. Most shops have a keen sense of what makes money and what doesn't. They shun any work that doesn't fall into Category 1. So...they might take in your greasy parts but it sure won't be cheap. By the time you drive to their shop, wait, then drive back....you've invested a lot of time, effort and money. It works well for an entire engine, but for a pair of valve covers? No way. Way too much intercourse required.

    A cabinet blaster is simply going to outclass a parts washer when it comes to surface prep and removal or rust and paint. I have both. Let's assume you are rebuilding a 1960's engine and you want the valve covers and timing cover ready for paint....the blaster is the only way you'll end up with a proper surface. That is, if you are doing high-end work and not an R&R job.

    A blast cabinet can handle small jobs piecemeal. Trips to the auto store will eat you alive.
    I'm sure geography plays a part in service availability.

    I still disagree though. When I'm doing fancy work the last thing I do is sandblast anything. I use an outfit that specializes in cleaning to remove everything but the basemetal without touching the metal. They do it with chemicals and electricity and tailor the process to suit my needs. It costs 25 cents a pound. I have had them do many engine blocks and high end restoration pieces.

    Sometimes the part is best baked off. If it's just a bunch of greasy paint and 1000 degrees won't hurt it baking is the way to fly.

    IMO, sandblasting is best to remove mill scale from cut and formed parts. Not a great way to prep anything for repair or restoration.

  6. Likes tdmidget, BT Fabrication liked this post
  7. #26
    Join Date
    Feb 2011
    Location
    BFE Nevada/San Marcos Tx
    Posts
    3,471
    Post Thanks / Like
    Likes (Given)
    3412
    Likes (Received)
    2180

    Default

    Agree, grease and paint need to be removed before part goes into blast cabinet. I used to use my blaster much more than it gets used today, most de-rusting is done with evapo, only time blaster gets used now is when I want a matte finish for paint adhesion. All I have ever used is glass beads.

  8. #27
    Join Date
    Nov 2004
    Location
    new york
    Posts
    9
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    0

    Default

    Quote Originally Posted by Gordon Heaton View Post
    I use a boron carbide nozzle and it is just amazing how little wear after hours of blasting with sharp silica sand. These nozzles are a little expensive up front but save a lot of money in the long run. They last several times longer than silicon carbide. The only downside, other than a little higher price, is the brittleness of the material. The ones I use come cemented into a form-fitted aluminum case. I'll never go back!

    The company that made mine:Boron Carbide Nozzles & Inserts | Malyn Industrial Ceramics Inc. has a wide variety of sizes and venturi styles, but you might have to do some adapting to get one to fit your gun.
    just got remote activated angled entry boron nozzle gun
    on Amazon for under 30 bucks.Huge improvement from trigger gun. Had previously done lighting,sealing,window,bottom drop out siphon abrasive uptake and 2 more critical up grades: siphon pickup hose is Flexilla garden hose with CPAP
    machine (non heated)hose as ''whip'' end in cab..durable whilst the most flexible kink free hose per dia in the world!! Anyone with Cpap machine will give you them as they get tons them

  9. #28
    Join Date
    Jan 2002
    Location
    Upstate NY -In the Flats next to the corn fields
    Posts
    9,656
    Post Thanks / Like
    Likes (Given)
    1950
    Likes (Received)
    2921

    Default

    Quote Originally Posted by norman View Post
    just got remote activated angled entry boron nozzle gun
    on Amazon for under 30 bucks
    Got a link?

    To the OP, you'll for sure want 1/2" hose with that bigger Quincy compressor, and 'full bore' with no restrictions from receiver tank to blast gun.
    Careful on pressure, too much and you'll break down your media quicker without more productivity. I use Alox at 60-70 PSI in my current siphon cabinet, but the (carbide) nozzle and air jet are opened up to about 40CFM. I have 185 CFM available, and things progress along (even for a siphon cabinet) at a very satisfying pace. CFM is a key factor. For example, a couple weeks ago, I blasted a 6 x 9 x 18" oil pan, on the outside, to a 'white' finish, all paint gone in about 8 minutes. I timed it just for kicks. Some of that time was spent flopping it around in the cabinet as well. Admittedly, there was one coat of paint, not several thick layers like your job. In that situation, you can probably do well by increasing the pressure.

  10. #29
    Join Date
    Oct 2017
    Country
    UNITED STATES
    State/Province
    California
    Posts
    1,526
    Post Thanks / Like
    Likes (Given)
    529
    Likes (Received)
    535

    Default

    We use a boron nitride nozzle on our 40cfm handheld blaster on a table inside of a booth made of a shipping container. It's about as much as you can handle for blasting small parts. We have one of those tapered metering valves and run aluminum oxide and it runs great.

    For big parts we use a 1/4" tungsten carbide nozzle on our pressure pot using the same sand in the same shipping containers. Pressures are around 30-60 psi for both *I think*.

    Nozzle life is no issue. We were eating through the hose couplings on the Clemco blast pot and replaced the lower coupling with a hose barb and the nozzle holder with an aluminum version and no longer have any issues.

  11. #30
    Join Date
    May 2006
    Location
    Seattle
    Posts
    2,663
    Post Thanks / Like
    Likes (Given)
    68
    Likes (Received)
    743

    Default

    Quote Originally Posted by Just a Sparky View Post
    Say, another question:

    What's a good quick disconnect standard to adopt for 1" air lines? I'm going to need to connect my skid unit to my receiver with no less than a 1" flexible hose.

    (Being able to rapidly disconnect equipment and roll it around on casters is extremely convenient for maintenance and housekeeping.)

    Something like these 'universal' twist-locks perhaps?

    Those are generally called Chicago fittings. We had many miles of air hose running around ships all coupled with these fittings and safety-wired. Even when I was 23 and much stronger these took all my strength to couple because the rubber grommets are designed to crush against each other. There are better full diameter couplers but they cost more.

    metalmagpie

  12. #31
    Join Date
    Jan 2002
    Location
    Upstate NY -In the Flats next to the corn fields
    Posts
    9,656
    Post Thanks / Like
    Likes (Given)
    1950
    Likes (Received)
    2921

    Default

    Ya, and when the rubber washers dry out and get less pliable they can be REALLY hard to connect. But who has time to replace the washers? What other full diameter couplers are you referring to?

    Quote Originally Posted by metalmagpie View Post
    Those are generally called Chicago fittings. We had many miles of air hose running around ships all coupled with these fittings and safety-wired. Even when I was 23 and much stronger these took all my strength to couple because the rubber grommets are designed to crush against each other. There are better full diameter couplers but they cost more.

    metalmagpie

  13. #32
    Join Date
    Dec 2012
    Country
    AUSTRALIA
    Posts
    5,254
    Post Thanks / Like
    Likes (Given)
    37
    Likes (Received)
    1911

    Default

    I never had any trouble with the connectors...the rubber section is hollow and inflates with air pressure for a positive seal...We used them up to 1 1/2 " size from compressor to air prep.,then 1 1/4" to blastpot,and proper blast hose ........proper blast hose has the reinforcing braid on the outside of the rubber ,so as the hose wears the braid stays intact........as soon as the braid is cut ,the hose bursts,and must be replaced ...........part of the experience of a blaster is to work the blast hose so it lasts ......a beginner can perforate a hose in a couple of hours if he kinks it.

  14. #33
    Join Date
    May 2006
    Location
    Seattle
    Posts
    2,663
    Post Thanks / Like
    Likes (Given)
    68
    Likes (Received)
    743

    Default

    Quote Originally Posted by dkmc View Post
    Ya, and when the rubber washers dry out and get less pliable they can be REALLY hard to connect. But who has time to replace the washers? What other full diameter couplers are you referring to?
    My experience is from the late '70s when I left the shipyard where I'd been building Navy guided missile frigates and went to work uptown building crab boats. The small yards around Seattle often had different air hose fittings. I hadn't yet gone to engineering school and so my understanding of the myriad mechanical mysteries around me was minimal. I can't tell you what kind I'm remembering, but here is a place you can start looking:

    Chicago Coupling — Hose Couplings

    metalmagpie

  15. #34
    Join Date
    Aug 2011
    Location
    new plymouth id
    Posts
    605
    Post Thanks / Like
    Likes (Given)
    48
    Likes (Received)
    173

    Default

    i use a lot of dixon boss hammer fittings on high pressure air little overkill for a standard air system but they seal tight and dont blow out the gasket

  16. #35
    Join Date
    Mar 2014
    Location
    United States, CT
    Posts
    158
    Post Thanks / Like
    Likes (Given)
    76
    Likes (Received)
    33

    Default

    I would just use a pipe union, pretty quick and painless to connect.


    Sent from my iPhone using Tapatalk

  17. #36
    Join Date
    Oct 2017
    Country
    UNITED STATES
    State/Province
    California
    Posts
    1,526
    Post Thanks / Like
    Likes (Given)
    529
    Likes (Received)
    535

    Default

    Quote Originally Posted by kineticmx View Post
    I would just use a pipe union, pretty quick and painless to connect.


    Sent from my iPhone using Tapatalk
    I don't feel like finely threaded couplings are pleasant near sand filled equipment. Maybe fine for inlet hose extensions


Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •