acid etch primer with hammerite ? yes/no

[jackassdave]

ive sprayed lots of things before with hammerite ,ususally not important things ,and not used a primer ,as it allways says ,spray onto metal.
but as im just about to spray the swing arm on the rt ,i would like to do a good job ,and thought a primer might help.
ill be takeing the swing arm down to bare metal in some places ,and to me this was the advantage of hammerite ,spraying straight onto metal .
so what is the collective thought ,with acid etch primer or not

 

[jackassdave]

or should it go ,red oxide /primer /hammerite .
ive never usually kept a bike long enough,for any of the paint to fall of anyway

 

[peepingtom]

i dont think a primer would hurt but personally i think a few coats of hammerite on it own will be fine . keep it in the house overnight so its nice and warm when you paint it, likewise with the paint .
good prep is more important but you already know that

happy chrimbo

 

[B4ndit]

I have just started to use acid etch. Not sure of the long term results. But I had some ally powder coated recently and they used two coats of acid etch. And I have recently touched up my rear swing arm on a Kwacker and used acid etch. Only time will tell if its any good. But it seems to be the thing to use at the moment.

That is until the EU catch on to how to bad it is for the environment. Then it will be back to using water based paints. Ala Junior School.

 

[MikeP]

Hammerite on to steel doesn't need any primer and it works fine without:

Painting bare steel with Hammerite takes more time than on to primer because the first couple of coats need to be very light to be certain that the paint bonds.

All that primer does is help paint bond but with Hammerite the rust inhibiting properties then have to reply on the primer coat which defeats the object somewhat.

I rarely use a primer. I prefer to just use clean thinners to be certain that there's nothing on the surface that might stop the paint from bonding. Don't wipe the excess thinners off, let it evaporate and then apply the paint.

 

[jackassdave]

thats a nice finish on there,yes i guess its all down to prep.

 

[corsicandreamer]

I thought acid etch primer was purely for use on aluminium ? but I could be wrong.

 

[MikeP]

It's for any ferrous surface. It can be used for stainless etc but the process for that is a bit too advanced for DIY.

 

[Rob Farmer]

I thought acid etch primer was purely for use on aluminium ? but I could be wrong.

Most of the cellulose primers are etching to a certain degree. It's just a small amount of acid mixed into the paint to allow it to bond to the substrate.

 

[justabof]

Remember that Hammerite claims to be ideal for applying direct to rusty metal. It's rust-inhibiting qualities work by bonding with the rusty surface.
If used on clean, non-rusty steel, I would use a primer first.
Works for me!

 

[Big Jets]

Thanks for posting I,m going through the same quandry as we speak ,I am gonna paint my frame with Hammerite smooth satin black and was gonna prime it but was not sure if it needed it .Cheers mind made up.

 

[jackassdave]

i painted mine without [rimer ,when it was drying it looked ok ,ill check tommorow and post some pics on the other thread

 

[Big Jets]

Nice one dave

 

[Cook1e]

RTFM!

"On bare zinc, aluminium and galvanised surfaces apply Hammerite Special Metals Primer before applying Hammerite Direct to Rust Metal Paint Smooth"

http://www.hammerite.co.uk/guide/direct_to_rust_metal_paint_smooth_finish.jsp

 

[jackassdave]

id have sold the bike ,by the time the paint comes off,that will stay on there longer than the bmw finish thats for sure

 

[Shep]

How come everybody gets a better job using hammerite than i do, it often looks good initially but is quite brittle and looses its jet black look after a few years, then when you need to refinish it, it needs sandblasting as most paints can't be applied successfully over the top.

A couple of coats of two pack epoxy primer applied to a shotblasted steel surface, then overcoated with a couple of two pack gloss topcoats does the trick. The epoxy primer is rock hard and totally waterproof once applied and if you want a matt finish it can be left just in primer. Lechler primer can be mixed to most colours

Jme of course

 

[team duvet]

Acid etch everytime

Acid etch primer every time on any bare metal, but remember primers are porous so will attract water/moister! Overcoat them with another primer ASAP.
Best process is ...
1. Acid etch spray 2 or 3 coats
2. Then apply 2 pack primer (had hardener in it) 2 to 3 coats
All of the above has to be done with a spray gun and suitable PPE or find your local friendly car/bike paint shop, but state you want etch primer then 2 pack!!! Some do not use etch!... Believe me!!
Or if you want a DIY job then hammerite will do I guess, but I have never used it. Remember always apply an Etch primer to bare metal.
If you need more information always ask, when buying any primer, for a product data sheet.
Note*** cellulose primers have no adhesion qualities at all!

Enjoy,
TD

 

[team duvet]

How come everybody gets a better job using hammerite than i do, it often looks good initially but is quite brittle and looses its jet black look after a few years, then when you need to refinish it, it needs sandblasting as most paints can't be applied successfully over the top.

A couple of coats of two pack epoxy primer applied to a shotblasted steel surface, then overcoated with a couple of two pack gloss topcoats does the trick. The epoxy primer is rock hard and totally waterproof once applied and if you want a matt finish it can be left just in primer. Lechler primer can be mixed to most colours

Jme of course

Good call Shep...forgot about Epoxy primers, again best overcoated with a 2 pack paint

TD

 

[Rob Farmer]

How come everybody gets a better job using hammerite than i do,

Probably because their not using a manky old brush thats painted a dozen narrow boats and been chewd by the dogs

 

[Shep]

Probably because their not using a manky old brush thats painted a dozen narrow boats and been chewd by the dogs

You spotted that then!