Cleaning off the grunge & grime

[s.leah]

Just wondered what people do to clean off parts and chassis prior to painting? What works best for you? Any product recommendations?

 

What's prompted the question is that I'm overhauling my Herald front suspension with new shocks, springs, trunions etc etc and I thought it would be nice with all those sparking clean new parts to paint the wishbones and maybe the vertical link.

 

I've got them fairly clean with generous use of superplus unleaded , gunk and a good rinsing. Ineveitably there's always a bit hanging on...

 

I suspect I'm on the money as far as cleaning is concerned, although using unleaded isn't exactly best practice

I'd also be interested to know what others do to remove underseal/waxoil?

 

I'd ideally like to get the surfaces nice and smooth, I assume it's just elbow grease and sand paper prior to priming (or hammeriting in my case )?

 

Cheers.

 

Simon

[mishmosh]

Industrial pressure washer helps. Also rotary wire brush.

[Clive]

For rust removal, search for electrolysis. It really works and with minimal effort.

 

As for cleaning, I have never had much success with using petrol except as an initial wash off. White spirit is better, and I use it in an old stockpot the missus was chucking out. Celly thinners is better still but evaporates fast. Useful for final rinsing. Or use spray carb cleaner or brake cleaner for the pre-paint rinse off.

 

Mechanical crud removal involves wire brushes, hand type first (less stuff to get in your hair/eyes/ears/nose) and then one on a drill or grinder.

 

I would not use hammerite these days, it is nothing like the old stuff. Bare metal should be etch primed, and a coat of black paint of your hoice. Chassis black is a cheap, but durable synthetic paint. Or splash out on POR15 but read up on using it first.

[Pete Lewis]

I am a brake cleaner convert, for degrease of components, not for chassis cleaning thats got to be

a mechanical clean to start with

but brake cleaner in 5 ltr cans from local factors is quite economical , you do need a deadicated spray

bottle as it will disolve most cheap plastic ones , like many products they have taken the working stuff out to make it healthy, even carb cleaner has lost its bite,

Iprefer Jizer for engine cleaning , smaells better than Gunk, and washes off with water

if you cant find any a cheap paint brush cleaner is always available as a Brush on wash off from any diy shop

[PeterH]

My local independent motor factor sold me 5 ltrs. Comma Hyper Clean. Works well for me - doesn't smell as bad as Gunk. Apply with brush allow to soak and pressure wash off.

[JohnD]

Cleaning with petrol?  Don't try this at home, folks.

Apart from the environmental hazard, exploding drains?

 

Sounds like all dirt and grime is already off your parts, so then the rust has to go.   For sand castings, the uprights, rotoflex wishbone etc,  that have a rough surface, no amount of sand paper will get a smooth surface (Why do you want it?).  But it makes difficult removing all rust  mechanically.     So use a chemical rust remover.    Organic acids dissolve rust, but always finish with phosphoric acid, whose reaction with rust leaves Iron phosphate, an insoluble salt, on the surface as a good key for primer.     

 

Smoother parts, eg radius arms, are best rust relieved with wire wool.   Then as before.

 

Hammerite?   It ain't what it used to be, since its formulation had to be changed to make it less environmentally aggressive.     I just use the above preparation, and paint with a good primer and an "exterior quality" house paint.

Don't be tempted by powder coating.  gets a lovely smooth ripple free finish, which cracks, lets water and salt in and then retains them next to the bare metal.

 

JOhn

[jamesdennison]

Lamp oil is pretty good, but you'll stink of citronella for ages.

[Mjit]

I've found Bilt Hamber Surflex HD to be very good.

[JohnD]

If you have a whole chassic and underside to do, the investment in a SnapOff Crud Thug.

Expensive and air powered, so there is a electric equivalent the Bristle Blaster, at no less cost I regret.

 

But you may be able to hire either.

 

Both look like ordinary wire wheels but work in a different way, more like a  descaling gun, with multiple tiny needles:

 

Blaster

 

 

Descaling gun

 

 

EITHER WAY - EYE PROTECTION!!

 

JOhn

[Colin Lindsay]

Sandblasting... I made a cabinet about ten years ago and it's superb, or was until I moved house and had to sell due to lack of room. The finish is brilliant, you can use whatever media suits your required part or finish, and it just blasts rust away right down to the shiny almost new metal. I'll make / buy another cabinet once my new garage is finished.

 

For a complete chassis my local blaster will do it to bare metal for £25, or prime it with grey primer after blasting for £40.

[Tiggers]

I find WD40 and it's equivalents with a few old wasking up / paint brushes a really good cleaning method, followed by a detergent (car wash & wax) and then meths or pre-paint to degrease prior to priming.