Cold galv or etch for steel hydraulic pipes

[conor1n]

Hello all

Quick question here as I can't seem to make up my mind.

I have a bunch of steel pipes for my hydraulic suspension in car.

I've cleaned them up via vinegar and wire wheel on bench grinder (steel is polished)

.. what would you put on them prior to black paint? I have some gold galv (cheapo autofactors) and some etch primer.

I plan on scuffing the pipes with some scothbrite prior to pain.

Cheers

Here are a few pics. After these pics they are going back in vinegar to get any pitted areas.. then I will tidy up the remaining areas with whatever it takes.

 

[Wildefalcon]

Etch? Then zg-90, then heat shrink tubing?

 

[Dcal]

Epoxy primer then whatever top coat you want.
Scuff them with 80 grit. You need a well sanded surface, not polished, for any primer.

 

[conor1n]

Yea I guess epoxy is a great way to go but it's not an option at the moment unfortunately.

I mean it's going back on the car and all that and I might live to regret it but there is just no time.

I think once these are all back in place I'll be using ACF50 or some Bilt Hamber wax etc going forward.

 

[conor1n]

OK... the only way to something is.....THE WRIGHT WAY...

Epoxy primer it will be.. I think I might actually have a little left over.

Thanks for the nudge.

80 grit seem harsh.. I have loads of marron scotch pad. What's that, like 320? Surely that is OK?

Also.. question.. some of the lines still have the flare on them like the pic. But some of them were a bit crusty under the flare fitting so the paint came away. Assuming all rust is gone etc.. how would you paint these?

I feel like I'm just going to paint in whatever way.. then keep the fittings dosed with ACF50 or whatever.

 

[Dcal]

Curious, why not?
Scrub that, just saw your last post.

The issue with the paint (or lack of) under the nuts, is galvanic corrosion where the dissimilar metals react.
It's ten times worse when you use cunifer pipe.
The pipes are perfect but the nuts are sized solid and will wring if you need to slacken them.

Plastic coating seems to be the standard solution but can crack and then the problems start.
Anything that exclude moisture and keeps the metals isolated will stop it so ACF sould do the trick.

Epoxy would be a good option but can be fairly thick and quite brittle.
Ceramic coating would be better still as it's very thin, but all this takes time and effort.
If it's worth it, is down to you.

I just painted some replacement brake pipes because the original were black.
I blasted them and sprayed with a 2K paint.
Am I mad?
Probably, but I was curious how they might last and I was painting other stuff anyway.

 

[MetalMonkey]

The issue with the paint (or lack of) under the nuts, is galvanic corrosion where the dissimilar metals react.
It's ten times worse when you use cunifer pipe.
The pipes are perfect but the nuts are sized solid and will wring if you need to slacken them.

I've switched to using brass or stainless fittings to solve this issue.

I've also painted steel pipes with 2K which seems to work reasonably well as it is thinner and more flexible than epoxy.