Sealing metal before painting

[rpeng]

I am trying to determine the proper way to seal carbon steel members that are joined by intermittent welds. The steel is cold-rolled ASTM A36 and the final product is epoxy coated with a chemical resistant tank lining (2 coats no primer, 5-6 mils DFT). The final product will be used in an indoor industrial environment (temp 35 - 125 deg F, high moisture, some salt).

I would like to seal the non-welded portion of the intermittent weld before painting while maintaining the appearance and abraision resistance of the product. What procedures/products are recommended? Thank you

 

[CoryPad]

Use a paintable sealant. For example:

http://www.geadvancedmaterials.com/.../ProductsAndServices/SeriesDetail/vp5700.html

http://products3.3m.com/catalog/us/...us_aad_3_0/command_AbcPageHandler/output_html

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[kenvlach]

Agree with CoryPad but verify epoxy-sealant compatibility. The epoxy product bulletin should give instructions on surface preparation. In some cases, one prepares polymer concrete by mixing dry (oven baked) silica sand into the resin and then grouts the (preferably sandblasted) cracks.