Summary for shot blasting aluminium profiles Discussion
Shot blasting aluminium profiles was discussed as an alternative to caustic etching for producing a satin matte anodized finish, since caustic concentration and temperature can cause shade variation. Sumit Lodha asked whether stainless steel shots would be suitable and whether they could produce a smooth finish. AF Kenton replied that stainless steel shot is not the best choice for a satin finish; if it must be used, he advised choosing the smallest size available and lowering pressure because any media will leave a dimple pattern. After Sumit said he would rather use glass beads, he asked whether a blower-based running blasting machine would be adequate or whether compressed air blasting was better. AF Kenton then recommended a pressure blast system over a vacuum system if budget is not a major issue. The thread therefore leans toward finer media, lower pressure, and pressure blasting for better control.
Q. Dear Sir,
I am doing anodizing and we are giving satin matte finish by etching the aluminium in caustic solution. But many times due to variation in concentration and temperature it gives different shades. To solve this problem we are planning to do mechanical etching with help of shot blasting the sections with stainless steel shots. My question is as follows :-
1)The media which we have cited Stainless steel shots is it alright ? We know we can also use glass beads but it is not compatible with shot blasting.
2) We want smooth finish, can stainless steel shots give us smooth finish ?
I have always got lots of help from this site and I really always appreciate the follow ups over the question. Thanking you in anticipation. Please guide me.
Sumit Lodha
Plating shop – Ahmednagar Maharashtra India
May 12, 2011
A. S.S. Shot is not the best choice for a satin finish. In fact, if that is the way you intend to proceed, try to select the smallest size you can get. Also remember, no matter what media you use, you will get a dimple pattern so reduce the pressure.

AF Kenton
retired business owner – Hatboro, Pennsylvania
Q. Thanks a lot sir for your reply. Shall I use glass beads for satin finish? SS shots the smallest size available is 0.1 mm will it do ? Please guide. Thanking you in anticipation.
Regards Sumit
Sumit Lodha [returning]
– Ahmednagar Maharashtra India
A. Glass bead is the better choice of the two and you don’t have to worry about the pressure.

AF Kenton
retired business owner – Hatboro, Pennsylvania
Q. Dear Sir,
Thanks a lot for your solution. I will better way go for glass beads. I wanna ask one more thing we are going for running type blasting machine, is the blasting done by blowers will be okay or shall we go for compressed air blasting ?
Once again appreciating your follow up over this issue.
Regards
Sumit
Sumit Lodha [returning]
– Ahmednagar, Maharashtra, India
A. If your budget is not a major problem, I suggest a pressure blast system over the vacuum system.

AF Kenton
retired business owner – Hatboro, Pennsylvania