Thread: "Reg - The series 2a build

Originally Posted by tibbsy

The dirt is all but gone using the wirebrush, but is there a grease / oil remover that would be recommended?

Have a talk to your paint shop, otherwise I would wash using a professional quality (i.e.expensive) degreaser, allow to dry and wipe down with turps.

John

Originally Posted by tibbsy

The dirt is all but gone using the wirebrush, but is there a grease / oil remover that would be recommended?

Rough it up first with abrasive paper; a flap wheel in the angle grinder would work well. Treat any rust with a converter and wire-brush, or sand after a couple of days.

Buy some tack-cloths and a degreaser from the paint shop when you get the primer and and top-coat; Septone Prepwash and Prepsol are two product names that spring to mind for de-greasing.

Then de-grease everywhere on the chassis, followed immediately it is dry with a tack-cloth, then apply the primer. Use Prepsol and and the tack-cloth between each coat,

Cheers Charlie

Tack cloths etc. aren't really required when painting a chassis with chassis black, surely? A bit of dust on a gloss body panel will look terrible, but a chassis?

It does need to be degreased, or the paint won't stick. Water based degreasers are OK for light deposits, but heavy oil contamination resulting from years of oil leaks mixing with dirt often require solvent based products. SuperCheap sell one, buried in between the water based versions. Make sure you get a degreaser not a "truckwash", as truckwashes often have waxes and other components designed to protect paint and make it look good - which is exactly what you are trying to remove! Then pressure wash, allow to dry and inspect. Repeat until no sign of oil and dirt remains! This process is ideally carried out before any further cleaning with wire brushes, because otherwise the brush gets covered in oily dirt which is then spread all over the chassis, and lovely new steel gets wet and starts to rust again.

It's also worthwhile to clean the inside of the chassis. I have a drain cleaner attachment for the powerwasher, that allows me to powerwash the inside of chassis rails. It's amazing how much crud comes out! After painting the outside of the chassis, the "clean" inside can be sprayed with something like Penetrol, using a suitable applicator, to stop it rotting from the inside.

Sandblasting is the ideal method of preparing a chassis (but not body panels, without special consideration), but even then you should clean and degrease prior to blasting, as the "wet" dirt is harder to remove with the sandblaster and the oil is left in a thin film - and washing the chassis AFTER sandblasting it just introduces more rust!

The basic rule is that paint retention is based on the weakest link. If your new paint bonds completely with the old paint, but that old paint drops off the chassis, you are no further forward. So if the old paint (and make sure its paint, not oil and dirt!) is hard to remove, then anything that sticks to that paint will stay in place. But if the old paint is easy to remove, then your new paint will fall off with it!

The other thing to consider is whether the new paint WILL stick to the old paint, or react with it, or just flake off. The only way to tell for sure is to test a small area. Roughing up the old paint is always required, it gives the new paint something to key to - gloss finishes don't take paint well.

Traditional bituminous chassis black doesn't normally require a primer, though will work with one and a primer may provide additional protection. The more advanced paints, up to and including the POR-15 and KBS products require far more intensive preparation. Between the two extremes are various products sold by Bunnings etc., urethane or epoxy based. You more or less get what you pay for. Bituminous chassis black is cheap and easy, but rust can spread underneath it without being seen. It used to be used extensively by second hand car salesmen wanting to make a rust bucket look good. The high end POR-15 style products can produce an excellent finish, from both functional and aesthetic viewpoints, but cost a small fortune and have very strict preparation and application requirements. KillRust and Metal Armour style products (and Hammerite) also work well, but require more prep than bitumen.

If you've stripped the chassis of all other components, and you want a long lasting vehicle and to make sure that no hidden weak spots and rust are left, it's worth investigating getting it sandblasted. Also, when everything else has been removed, PeterG has a technique of putting a pole through the PTO holes and balancing the whole thing on supports at each end - I copied him but made a pair of stands to support a chassis on a length of 2"NB pipe, so the entire chassis can be rotated easily. It removes the need to crawl about trying to paint to underside!

Originally Posted by Warb

Tack cloths etc. aren't really required when painting a chassis with chassis black, surely? A bit of dust on a gloss body panel will look terrible, but a chassis?

Well; as I had recommended sanding or brushing, both of which generate dust, a bloke would be mad to spray expensive paint onto dust, when for the lousy $2 it costs for a tack-cloth and the 5 minutes of time expended, it more or less guarantees that the paint will stick.

Much the same as the advice you give later in your post,

Cheers Charlie

Originally Posted by Warb

Tack cloths etc. aren't really required when painting a chassis with chassis black, surely? A bit of dust on a gloss body panel will look terrible, but a chassis?

It does need to be degreased, or the paint won't stick. Water based degreasers are OK for light deposits, but heavy oil contamination resulting from years of oil leaks mixing with dirt often require solvent based products. SuperCheap sell one, buried in between the water based versions. Make sure you get a degreaser not a "truckwash", as truckwashes often have waxes and other components designed to proect paint and make it look good - which is exactly what you are trying to remove! Then pressure wash, allow to dry and inspect. Repeat until no sign of oil and dirt remains! This process is ideally carried out before any further cleaning with wire brushes, because otherwise the brush gets covered in oily dirt which is then spread all over the chassis, and lovely new steel gets wet and starts to rust again.

It's also worthwhile to clean the inside of the chassis. I have a drain cleaner attachment for the powerwasher, that allows me to powerwash the inside of chassis rails. It's amazing how much crud comes out! After painting the outside of the chassis, the "clean" inside can be sprayed with something like Penetrol, using a suitable applicator, to stop it rotting from the inside.

Sandblasting is the ideal method of preparing a chassis (but not body panels, without special consideration), but even then you should clean and degrease prior to blasting, as the "wet" dirt is harder to remove with the sandblaster and the oil is left in a thin film - and washing the chassis AFTER sandblasting it just introduces more rust!

The basic rule is that paint retention is based on the weakest link. If your new paint bonds completely with the old paint, but that old paint drops off the chassis, you are no further forward. So if the old paint (and make sure its paint, not oil and dirt!) is hard to remove, then anything that sticks to that paint will stay in place. But if the old paint is easy to remove, then your new paint will fall off with it!

The other thing to consider is whether the new paint WILL stick to the old paint, or react with it, or just flake off. The only way to tell for sure is to test a small area. Roughing up the old paint is always required, it gives the new paint something to key to - gloss finishes don't take paint well.

Traditional bituminous chassis black doesn't normally require a primer, though will work with one and a primer may provide additional protection. The more advanced paints, up to and including the POR-15 and KBS products require far more intensive preparation. Between the two extremes are various products sold by Bunnings etc., urethane or epoxy based. You more or less get what you pay for. Bituminous chassis black is cheap and easy, but rust can spread underneath it without being seen. It used to be used extensively by second hand car salesmen wanting to make a rust bucket look good. The high end POR-15 style products can produce an excellent finish, from both functional and aesthetic viewpoints, but cost a small fortune and have very strict preparation and application requirements. KillRust and Metal Armour style products (and Hammerite) also work well, but require more prep than bitumen.

If you've stripped the chassis of all other components, and you want a long lasting vehicle and to make sure that no hidden weak spots and rust are left, it's worth investigating getting it sandblasted. Also, when everything else has been removed, PeterG has a technique of putting a pole through the PTO holes and balancing the whole thing on supports at each end - I copied him but made a pair of stands to support a chassis on a length of 2"NB pipe, so the entire chassis can be rotated easily. It removes the need to crawl about trying to paint to underside!

Please; Where, oh where do you get Hammerite from over here? I've been looking for it ever sice I moved here without success.

Go to inspirations at Oxenford, they have all the hammerite you will need.

Originally Posted by Ratel10mm

Please; Where, oh where do you get Hammerite from over here? I've been looking for it ever sice I moved here without success.

Looking at Hammerite Australia - Metal Paint, it looks like it's sold through The Flood Company, who also are responsible for Penetrol.

I also note that Permanent Paint Coatings (www.pppco.com.au) sell it online, as well as POR-15

I used to use Hammerite (and Smoothrite) in the UK, where it was de rigeur to have Hammerite on old cars. Recently I've been testing out the POR-15 and KBS products, as well as various metal paints available from the DIY stores. So far I'd say that most of them in fact work fairly well! I've had some cast iron pieces that I sandblasted and painted with KillRust (primer and top coat) a couple of years ago, that have been out in the weather since they were painted and don't show any signs of failure.

Originally Posted by chazza

Well; as I had recommended sanding or brushing, both of which generate dust, a bloke would be mad to spray expensive paint onto dust, when for the lousy $2 it costs for a tack-cloth and the 5 minutes of time expended, it more or less guarantees that the paint will stick.

Much the same as the advice you give later in your post,

Cheers Charlie

Perhaps, but the original poster stated he was going to use chassis black, which - lets be honest - isn't going to be affected by the small amount of dust that should be all that is left at that point. Tack rags are the last 0.1% dust removal "perfection" product (used after vacuuming, air dusters etc.), whilst bitumen chassis black is the other end of the scale!!

On the other hand, if I was painting the chassis with a thin film product for show, then I'd certainly want it totally dust free!