I don’t believe this problem has surfaced or been reported in the past. About 18 months ago, I purchased a plastic 4 oz bottle of Mclube 444 from Schaff, who evidently repackages bulk material into this smaller size, and fashions a top to hold a daubing applicator. After about 12 months, I noticed the solvent had an orange cast, and that there was significant corrosion of the applicator’s wire "stick". Closer examination revealed specs of a brown solid mixed with the settled product solids. In my opinion, this bottle of material is now un-useable. I contacted Mclube, who verified that the product's carrier solvent (n-propyl bromide) will react with white or ferrous-based metal over time. Their own packaging containers, when metal, are lined to prevent this problem. Their recommendation is to store this product in glass or coated metal containers.

I have alerted Schaff, who uses a third party to supply the bottles and applicator tops. They plan to check their current inventory of item 444-4 (Schaff’s product code) for evidence of the corrosion problem. Logically, shelf life and other factors enter into the picture. I hope they find a way to redesign the applicator with a non-metal (non-reactive) “stick”. In the meantime, I plan to store my product in a glass jar with sealed top, and expose the solution to the applicator only when using the product. Another option would be to purchase Mclube in aerosol form, which would be acceptable for situations in which overspray can be tolerated.

Thanks for letting us know, Fred. I have the aerosol, and if I need a judicious application, I spray a little into the cap and then use an artist's brush.

If I may bend your thread a bit, I'm interested to know how 444 differs from 1758 (is that right?) and their other mold release products, as far as piano applications go.

--Cy--

Thanks for asking, Cy - you may have found another solution to the problem (there's a bad pun). I think the product you are referring to is Mclube 1725. The difference between that and the 444 is down to the carrier solvent. The 1725 uses a mixture of heptane butyl acetate and ethanol. Interestingly, the solids are exactly the same, which suggests that the product performance for a tech's use would not be different. Furthermore, Mclube does not believe there would be the same reactivity issue with ferrous metal as with the 444.

I am unsure whether Schaff specifically chose to repackage the 444, ie if other concerns confronted them in handling/shipping the 1725 (for one, the 1725 is more highly flammable). When I get a chance, I will update Schaff and let them decide how to proceed.

Yes, 1725 it is, Fred! Thanks for answering my question. I remember that the 1725 had to be packaged separately because of its flammability.

If there's a test I can do for you, let me know. I don't think I have that specific Schaff container.

--Cy--

Final update from me on this thread. Schaff stated that they will now supply the 444 Mclube liquid with the daubing applicator packaged separately (ie not suspended in the product). So, its basically up to you to clean/store the applicator separately (or take your chances wrt corrosion).