We produce pumps & fluid motors that may or may not be painted before shipment to customer. Machined mounting flange surfaces are always unpainted (approx. 125 microfinish). We clean the cast iron components in automatic washers containing recommended levels of cleaner (which also contains a rust inhibitor), build the pumps/motors, test/break-in on test stand with hydraulic oil (also has some rust inhibiting properties), plug pump/motor, wash again (in same washer) to remove test oil, paint (or not), apply WD-40 to mounting flange area, and heat seal in an appropriate size 4 ml. VCI poly bag with a yellow VCI chip. (Apparently) Plenty of VCI protection.
Certain overseas customers are receiving our shipments with "freckle spot" rust, even though we go to these lengths to prevent rust from occuring. After doing some research it seems that the use of WD-40 may actually inhibit the ability of the VCI chemical to prevent rust since the mounting flanges are no longer bare metal. The use of VCI bags & WD-40 is stuff I refer to as "manufacturing legend"--no one really knows how it got started, but it is clearly not effective. It was done "on the fly".
I experimented with a couple of formulations of Daubert's Nox-Rust, and found that it prevented rust alright, but left an objectionable film that we didn't want the customers to have to remove. I am currently experimenting with VCI bag material designed specifically for ferrous metal (it would be a must to keep mounting flange's bare metal clean before bagging) and a commercially available non-dimensional rust preventative liquid that can be sprayed on the bare metal (pumps/motors would then be heat sealed in a PLAIN poly bag).
While my experiments continue to run does anyone have any good results to share regarding rust prevention?
BigCal
Certain overseas customers are receiving our shipments with "freckle spot" rust, even though we go to these lengths to prevent rust from occuring. After doing some research it seems that the use of WD-40 may actually inhibit the ability of the VCI chemical to prevent rust since the mounting flanges are no longer bare metal. The use of VCI bags & WD-40 is stuff I refer to as "manufacturing legend"--no one really knows how it got started, but it is clearly not effective. It was done "on the fly".
I experimented with a couple of formulations of Daubert's Nox-Rust, and found that it prevented rust alright, but left an objectionable film that we didn't want the customers to have to remove. I am currently experimenting with VCI bag material designed specifically for ferrous metal (it would be a must to keep mounting flange's bare metal clean before bagging) and a commercially available non-dimensional rust preventative liquid that can be sprayed on the bare metal (pumps/motors would then be heat sealed in a PLAIN poly bag).
While my experiments continue to run does anyone have any good results to share regarding rust prevention?
BigCal
