"Shop" primer/etching?

[moxieforme2]

Any thoughts about what is best for 'shop' priming, or etching small prices that are sandblasted and waiting be finished primed and painted at a later time.

Is there a best method/product(s) you are satisfied with that has proven itself over time. Yes, I know opinions vary, but every one desires the very best for their time and efforts.

Anyone with prior experience and are satisfied feel free to chime in.

Jim Masters.

[55 Fargo]

Any thoughts about what is best for 'shop' priming, or etching small prices that are sandblasted and waiting be finished primed and painted at a later time.

Is there a best method/product(s) you are satisfied with that has proven itself over time. Yes, I know opinions vary, but every one desires the very best for their time and efforts.

Anyone with prior experience and are satisfied feel free to chime in.

Jim Masters.

I would simply treat the freshly media blasted pieces/parts with a phosporic based acid product, like Picklex 20, then either use a 2 k Epoxy Primer, or Rustoleum rusty metal primer, use the rusty metal primer either in aerosol format, or use the canned stuff reduced up to 40% with automotive enamel reducer, then spray on with paint gun using a 1.3 to 1.5 tip, a cheapo HVLP gravity feed gun work well for this.

As the said parts will be in storage indoors, the Rustoleum needs to fully cure about 2 weeks, then any enamel or Urethane paint can go over with no issues.If you go with epoxy, just check the re-coat windows, but it will need a scuff after a short period.

If these are small panels, ie exterior panles, the same can be done, just keep in mind if using Rustoleum primer, to give this a long period to fully cure, after this, anything goes, 2 k urethane primer, lacquer based primers, epoxy primers, auto body fillers, etc.

Do not use any acid etching primer over the above mentioned products, acid etch primer is to be used only on bare steel, then I would go over this with epoxy primer, read all instructions.

Personally I would skip the etch primer, and go with eiother of the systems/ primers I have mentioned......Fred

Edited August 16, 2009 by Rockwood

[martybose]

As many of you know, I work in a shipyard. ALL of our steel is blasted with either sand or steel shot to give it a profile that paint will stick to. We usually put on a weldable primer immediately afterward, then cut and fit it, weld them in and then do final coatings (up to 5 coats in some cases).

Marty

[Plymouthy Adams]

yeah, I know well the shipyard green primer that will take you breath away and all who are within 20 compattments of the area being painted..that stuff is loaded with Toulene

I will say this about your paint...what is your top coat brand and ask them for the compatable primer...that way no one has confused you with this and that and your peace of mind on known compatability will go a long way for those who have not much experience in various paint products

[dezeldoc]

Do a search this has come up a lot lately.

PS, just remember the less mill thickness the better, it will be less likely to chip as easy as thicker mill thickness.

Edited August 16, 2009 by dezeldoc

[greg g]

for small to medium pieces SEM makes a rattle can self etching primer, Body shop supply store sell the SEM Brand.

[Frank Blackstone]

I got a lesson in not applying too many coats of primer. As Doc says too many can cause cracking of chipping. About 1 mm per coat of wet primer is an estimate. I hear about 4 coats is plenty and finish up with 400 grit wet sandpaper. Too fine of grit will not give the tooth the paint needs to adhere. Do not put to much catayst activater in as that can over catalze the primer and also cause it to crack.

[chopt50wgn]

There is no need to use etching primer when the surface is already blasted. The surface already has a "tooth" for the primer to bond to. If you use an epoxy based primer, you won't have to worry about any surface rust and the primer will bond very well.