Presto Black BST4 from Birchwood Technologies is a brush-on cold blackener for iron and non-stainless steels that is formulated to produce a durable black finish within 30 seconds.
In the aerospace industry, BST4 can be used as a fast-acting blackener for rebuilding processes on pistons, bearings, crankshafts and re-machined areas or other reworked metal parts. It also is suited for use in prototype and re-machining applications, and can serve as a manual black oxide process for simple brush-on needs.
In the machine shop, the solution can be used to blacken re-machined areas or reworked metal parts. It also is suited to quickly repair scratches or damaged areas on parts previously black oxide finished. The resulting finish has a good black color that blends well with existing black oxide finishes and will withstand the same degree of salt spray exposure as the original black oxide, the company says.blog comments powered by Disqus