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-----"Solutions to Problems Blasting Stainless Steel"
Q. Hi,
We want to produce a consistent finish on a bread bin/box that will be pressed in 0.5mm bright annealed 304 stainless sheet. We plan to do the press brake work required and then bead blast both sides while supported on a shaped support to stop any distortion.
My questions are:
Is it easy to bead blast by hand to produce a consistent finish on what is simple curved shape with a couple of pressed folds?
If I was to have the sheets bead blasted ahead of folding would the bead blasting work harden the sheet making press folding problematic? ⇦ Answer?
Many thanks,
designer /maker - Bath, U.K.
October 20, 2025
⇩ Similar, related, Q&As -- oldest first ⇩
Q. We manufacture packaging machinery for the food industry. Our machine bodies are generally fabricated from 4 mm 304 2B finish stainless steel. After fabrication, grinding and sanding the bodies are glass bead blasted. Our problem is that some machines in certain environments (i.e., chlorinated water in the same room, cleaning and sanitising agents) the machine bodies tend to discolour. A rust like brown stain appears on the stainless. It also appears on some 304 shafting and any case hardened and ground linear bearing slide material discolours and becomes pitted.
Any advice ?
craig pullen- sydney nsw
1999
A. Hi Craig. If the glass beads have previously been used on steel you cannot use them on stainless or you will have this problem.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
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A. Stainless does not mean immune to corrosion. Any environment with chlorides can results in corrosion of type 304 SS. The previous comment about abrasives is right on. Contaminated grinding media can also cause a problem.
I suspect that your problem is a combination of the environment and the surface condition resulting from the bead blasting. Microscopically, the bead blasted surface consists of many small crevices. If water with chlorides gets into these crevices, the potential for crevice corrosion is great. Ground surfaces are also prone to these crevice corrosion sites. Once the corrosion starts in these crevices they will be prone to continued corrosion unless the surface finish is improved. Case hardening diminishes the corrosion resistance in general and may not require crevices to initiate pitting corrosion.
Larry Hanke
Minneapolis, Minnesota
A. Dear Craig
As a supplementary to my peers which gave you bright answers I suggest you will passivate your equipment as soon as you finish your glass blasting.
As you know or don't the stainless steal can stand only 2 hours in Salt Spray ASTM B117 . This requirement is by the Military Standards (QQ-P-35C (canceled) [link is to free spec at Defense Logistics Agency, dla.mil]) requirements and this is quite low requirement speaking about Passivated Stainless Steel. If the Stainless Steel is unpassivated the ability of the Stainless Steel to approve the requirements is even lower .
Yours Sincerely
Yehuda Blau
YB Plating Engineering and Quality - Haifa Israel
Q. We have been asked by some customers to supply our food processing machinery with a glass bead blasted exterior finish. We expect this is much less costly than polishing, and would appreciate any info. regarding surface preparation of the stainless steel (mill plate), bead suppliers, correct bead size, and estimated bead usage/sq.ft. to achieve an acceptable finish. Any illustration, characterization, or specification of a typical bead blast finish for this industry would also be a big help.
Many thanks,
Dave Munsell- Utica, New York
2003
A. Dave,
An abrasive blast finish (glass bead) is a lot rougher and faster to achieve than a polished finish; however, there are other considerations. Selecting the right system is important and a lot of that depends on your volume. There are 2 types of systems to consider besides size. One is a vacuum and the other is a pressure blast system. I suspect that the size of your parts may lend themselves for you to consider an automated system. Hand held methods and the human factor may effect the results and/or produce non-uniform looking parts over large areas. You have a lot to consider and you should consult a knowledgeable sales person and/or company who produces automated systems.
AF Kenton
retired business owner - Hatboro, Pennsylvania
2003
Cleaning glass bead blasted stainless steel
Q. We have designed two joinery units for an interior project. The finished cladding is 3mm glass bead blasted stainless steel. During installation of the units, and the AV equipment inside, the s/s has become marked with fingerprints.
We have been advised by the builder that he has tried to clean them off with warm soapy water. They appear to be cleaned off, but as the s/s dries, the fingermarks reappear. Unfortunately, I am not sure if it is a specific type of grease or just general oil and grime.
I did have a sample of glass bead blasted s/s on which I rubbed olive oil and general handling. This I was able to clean with soap and water.
There is not the opportunity to douse the units in water, nor spray with substance as the doors have ventilation slots cut into them for the AV equipment behind. I hope that you may be able to help.
Kind regards,
architecture - Sydney, NSW, Australia
2003
A. In this case, you may have to try a solvent. It sounds as if there is more to it than just finger prints.
AF Kenton
retired business owner - Hatboro, Pennsylvania
A. G'Day,
Your problem definitely sounds like "rusty fingers" As a Plastic-injection mould finisher/TIG mould repairer I have to be very careful about delivering the agreed finish to a client especially if it is a high lustre or micron finish. This agreed finish does not include spots of unknown origin or doubtful finish. It sounds like whoever handled your S/Steel project had a high acidic value in the fatty acids... we all have on our skin i.e., the palms of the hand. Various foodstuffs including alcohol can alter the alkalinity of those fatty acids....some people just have naturally occurring "acid hands".
If you still can clean down the whole area again with solvent and allow it to dry. Doing the glass bead treatment again would now be your best recourse as a follow up.
Michael Hein
- Sydney, NSW, Australia
A. Try using isopropyl alcohol ⇦ on eBay or Amazon [affil link] on a soft cotton rag, it works well to remove fingerprints on brush finished or bead blasted stainless steel.
Jim Sivertsenrefining & alloys - Alden, N.Y., U.S.A.
Q. I have stainless steel covers 18" x 18" x 4" that get Aluminum Oxide and Glass Bead Blast from a job shop. Over the course of this job, the parts have come back with tiny black spots on them (would not come out with thinner) marks and abrasions. The marks are shiny and seem to be on top of the bead blast. The abrasions almost look like roller marks. After the part is done it gets packed inside of a plastic bag and then in a cardboard box. Anybody have any ideas.
Bob Manzella- Bohemia, New York
2003
A. Have you tried different mesh size of glass beads? Have you tried wet blasting? I may suggest you should try those alternatives.
Timur Ulucakaluminum extrusions & finishing - Istanbul, Turkey
A. It sounds like you or your subcontractor has a contamination problem. Because blast systems recirculate the abrasive blast media they are subject to contamination from a number of sources. I suspect that is the case here. Even if the subcontractor changes all of the media, it is still possible to encounter the same problem unless the cabinet is cleaned and hoses changed.
AF Kenton
retired business owner - Hatboro, Pennsylvania
A. The marks you refer to are probably from the blast job shop rolling hence scratching the profile left by the blasting. i.e., they are wearing down the profile making it shinier or darker than the matte finish of the blast. Talk to your job shop about being more careful with handling your parts. This is a common problem.
Jeff chadwick- mississsauga,ontario,canada
2003
A. You need to send your cover to someone who knows to handle the material. After they're blasted they need to be washed or wiped down then wrapped in soft foam, then shrinkwrap with plastic.
Cardboard will scratch stainless if it is slid on it. The shiny marks that look like roller marks could be from the material finish before blasting; if the material was #4 it would have about a 180 grit shiny grain. Which is hard to blast because it would have to be DA sanded to a 80 grit. The best material finish for bead blasting is 2b or mill finish. Also stainless needs to be blasted with clean sand most blast shop do not tell you that because they don't care.The cover might rust if the sand was contaminated with carbon steel (black Spots). Most stainless specialty shops will blast stainless and only stainless in their booths. I only use glass beads unless I need a real rough finish. They should be able to show you blasted samples so you can pick out the finish (grit) you want.
stainless steel welding - Kenosha, Wisconsin
July 30, 2009
Architect can't get fingerprints off bead blasted stainless steel
Q. I'm an architect in NYC and I've specified glass bead stainless steel on a number of projects, primarily for kitchen counter tops but for other items as well. In addition to specifying this for aesthetic reasons, the finish also has the advantage of not picking up fingerprinting or other grease smears.
Recently, I've specified it on a project out of state - in Colorado and the subcontractors are having a hard time matching my control samples. The control samples that I have are from these previous jobs, and the original fabricators tell me their finish is proprietary. I know that there must be some standards for this finish but I'm having a hard time finding them. The finishes that they have submitted have been both sandblasted and glass bead blasted - but none have been as deep into the finish as I want. And, all of the samples they have submitted show as much finger grease as a brushed finish. This is for sheet goods as well as structural T's, tube sections, etc. -- lots of different stock material and I'm aware that it will take differently depending on the material. What I care about the most is the sheet goods, since it will experience the most wear.
Any recommendations on standards or cleaning agents that can be used on stainless steel kitchen counters that will be okay with hot cooking utensils or pots on them? ⇦ Answer?
Lea Cloudarchitecture - New York, New York
2004
Aluminum Impregnation in Stainless Steel? - Glass Media Blasting
Q. Hi,
I produce some parts made of 303 and 304 stainless. These have always been finished in house using glass beads in a media blasting cabinet. The cabinet is only used for the 303 and 304 stainless steel. The volume is now too great for my Harbor Freight blast cabinet so have been asking around locally for a media blaster. The only blaster with a "clean" glass bead cabinet (not used for rusty car parts) does only aluminum for electroplating. My question is: Will the aluminum dust from their parts impregnate my stainless to create an aluminum oxidizing situation on the exterior of the stainless parts similar to what happens if normal steel impregnates the stainless? Of course the aluminum wont be "rusty" looking but still possibly give a hazy oxidized look eventually? I would think the aluminum dust would not have enough mass to impregnate the stainless. However I do not want to take an inexperienced guess and send out a product that may have the appearance of aluminum oxidation later. And for their sake would my stainless contaminate their processes (Anodizing and Alodine)?
Any help would be greatly appreciated. ⇦ Answer?
- Paradise, California
August 24, 2018
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