AT 400 vs the BP 400 Twin Wire Electric Arc Spray Equipment

At Thermal Spray Depot we are proud to be a distributor for the AT 400 twin wire electric arc spray system manufactured by Thermach. We have been asked if the AT 400 by Thermach is the same as the BP400 built by Praxair Tafa; well it is not; but they share an interesting history in arc spraying.  In applications where you require electric arc for your metal spray application, the AT 400 is superior to the Praxair Tafa BP 400. Additionally, some ask to compare the AT 400 to the 8830.

The BP 400 was originally designed in Wisconsin at Miller Thermal, which was part of Miller Welding at the time. Through various acquisitions, the Miller Thermal Group became part of Praxair.  When Praxair purchased Tafa, they decided to move the manufacturing of the Miller Thermal spray equipment to the northeast.  Some of the original design group and manufacturing group of Miller Thermal decided to stay in Wisconsin and from what is now Thermach.

After Thermach was formed, they took on a project to design a new arc system.  Both units look similar, but there is significant internal changes to the AT 400. The gun parts of the two units are not interchangeable even though they look similar. In addition, improvements to the wire feed unit, such as the quick change drive rolls, are not interchangeable.

As one final note, the lightweight and rugged design of the AT 400 make it the obvious choice over the 8830.

To see the superior features, please click on this link:

AT 400 Twin Wire Electric Arc Spray

Keep asking questions!


Surface Preparation for Thermal Spray Coatings

What is the best way to prepare the surface before thermal spray?

Grit blast is the best way to prepare a surface for thermal spray. This is after all the oil and grease have been removed from the part to be sprayed. The purpose of grit blasting is to remove all oxides and foreign material from the surface being sprayed. More importantly, the grit blast operation results in a surface that has many pits and textured areas where the thermal spray can attach to and lock into. The most common material used for grit blast is aluminum oxide and chilled iron.

For a more in-depth discussion, please go to this link:

Surface Preparation for Thermal Spray