Cleaning by Sandblasting

By swnorris (****)

Date 04-11-2006 13:07

It's more than appropriate, but why go to that expensive extreme? Do you have materials that are heavily and/or completely rusty?

By CHGuilford (****)

Date 04-11-2006 13:17

Also keep in mind that spatter sticks to blasted steel like there's no tomorrow. Anti-spatter products or some type of shielding might be needed to avoid some tough clean-up.
If the steel is going to be painted, realize there wil be no profile on the welds for the paint to adhere to unless you sweep blast the welds afterwards.
Chet

By focussaint Date 04-11-2006 13:21

Sandbalsting is not an expensive option for us, however, I'm developing a WPS for internal processes and I wanted to be sure it wasn't impregnating the material with glass. To answer your other question, since the components are carbon steel, the manufacturer adds a paint-like coating which dirties up the weld (so I've been told).

By jwright650 (*****)

Date 04-11-2006 13:35

Pipe usually has a coating that we like to clean off before welding. That stuff looks to me as if somebody turned thier kids loose with a bucket of clear laquer and a brush.
John Wright

By focussaint Date 04-11-2006 13:47

Thank you, all for your comments. Can anyone tell me if there are any guidelines in ASME Sections VIII, or IX that might restrict the use of sandblasting or other cleaning method. A general direction would be helpful.

By swnorris (****)

Date 04-11-2006 15:45

John,

The lacquer coating is supposed to be a rust protector for pipes used in sprinkler systems. We don't like it either. We always specify "black pipe" when ordering, so we don't have that problem.

By NEQA

Date 04-14-2006 19:25

Can't recall ever seeing where VIII and/or IX restricts the use of sandblasting or other cleaning method - but, then again, I wouldn't expect too. I think of VIII as a construction code only and I look elsewhere (ASTM) for workmanship, finish, etc. What do you mean by "other cleaning method"?

A108 says (paraphrasing here) that the material is to have a bright smooth finish obtained by cold drawing, rolling, or polishing. To me, that means no blasting is allowed. Anyway, if you were going to blast, I'd think the engineer would want to first see and approve your blasting procedure - I know I always do. And unless you can show me why you can't polish, we would never approve blasting. The fact that blasting is not an expensive cost factor for you is not a good reason.

Mr. Guilford is right on point regarding spatter sticking to blasted steel. Any savings you might realize by blasting will be more than swallowed up by the time and manpower needed to remove spatter.

By Mike D K Date 04-13-2006 20:53

i have the same question , i have seen aluminum oxide used and i wonder if the deep profile and aluminum oxide entrappment is causing rt failure in the root pass.

By Mike D K Date 04-13-2006 20:54

i wonder if aluminum oxide is the cause for some root pass failures will the alum get into the profile of the steel?

By focussaint Date 04-14-2006 19:32

I should probably review this with a metallurgist. If I decide to have an analysis performed, I'll post the results. Thanks to all for your comments.