metal prep before Epoxy

[islandjj]

Hi
I'm just in the process of painting my MGA. I've stripped the panels back to bare metal, welded patch panels etc, then washed with phosphoric acid. Do I now wash with water to remove any phosphoric ? do I wash with thinners to get rid of any traces of oil/grease. The bare metal looks slightly etched from the phosphoric but there is black spots where its reacted with traces of rust. Its letchler epoxy . My garage is about 20 C at the moment , although its states 25 - on the tin. So I'd appreciate some advice

 

[richie00boy]

You need to remove the phosphoric because it will reduce the effectiveness of the epoxy, which already has a zinc phosphate etching agent.

I usually wash over just prior to painting with citric acid and scotch pad then a rinse with plenty of water maybe with a touch of bicarbonate of soda added for neutralisation. Then give the panels a flatting with P240. Finally a wipe over with panel wipe and on with the paint.

The paint you have will be fine at 20 degrees. As long as it's always above 15 you will be ok.

 

[langy]

As Ritchie said really but thinners is never used for prepping, you need panel wipe for that, as for the temp its still a little low, the important thing is the temp of the panel more than the air.