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Did my new chassis in epoxymastic. Two part paint. Hard and yet not brittle.  Works for me. 

Tim

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There is only one chassis paint and that is POR15. I have used this on my other car and will be on my TR6 next week end. It is quite simply 'tough'. Watch their demonstration video for proof and I can vouch that it is very tough paint indeed.

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My first choice for protection and durability would be a good 2 part epoxy primer with an epoxy top coat if necessary.  But I also prefer brushing a chassis, because of all of the recesses that would be hard to cover adequately with spray.  My favoite epoxy is too thin bodied to brush, so I also used POR15.  It is very tenacious, and probably as tough as epoxy.  It needs to be top coated, though.

Ed

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++ for POR15 Chassis Black hard as nails, flows and dries like a spray finish. Needs two coats close together. Only thing is don't use too big a tin once opened its best used quickly as any air/moisture cures it. Pour into a separate container and wipe the tin lip and put polythene between the lid/tin or you won't get the lid back off!

Use cheap brush and bin it as they are not worth trying to clean.

Andy

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This is interesting POR15

I will be at the chassis paint stage later on

if the chassis goes off for repair then i guess it will be shotblast and primed when it comes back

can i paint this stuff straight on and does it need a top coat to seal or just two coats of the same (bit like offshore stuff)

it states use metal prep to dissolve rust and give a zinc phos undercoat for better adhesion, i could get the chassis repairer to do this

i was thinking about galvanising the chassis then painting but for the miles etc the rebuilt car will do it will out live me so this DIY will be a lot cheaper

david

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POR does not need a top coat unless it will get UV light so areguably you do not need a top coat. However I did use their chassis black top coat last time and will use thier Top Coat this time.

POR15 needs two coats.

POR15 takes between 2 and 6 hours to dry (but longer to cure). Recoat when only just tacky, not dry, so arguably you simply start again when you have got to the end of first coat.

If you continue with Top Coat, simply the same again and start when POR15 base coat is just tacky again (Last time I think I did the top coat the next day and all was fine). Top Coat dries between 30 to 60 minutes so follow with second Top Coat. I am expecting it to take betweem 5 and 10 hours to brush all this next weekend. Last time I sprayed.

If you are sandblasting, they should spray with a phosphate coating to stop immediate rust. That is sort of what Metal Prep is so no need to use this on a sandblasted chassis sprayed with phosphate.

Use Metal Prep on all other stuff such as suspension, drive shafts, etc. It is a bit funny in that you do not think it works and usually seems to make the metal rust a bit. It is supposed to and simply paint over with POR15. I would always clean off as much rust before using Metal Prep such as a DIY grit blaster or needle gun. Basically get off as much rust as you can but POR 15 does stick to 'clean rust'.

I may report back in two weeks once I have finished.

 

Edited by Richard Pope
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One thing perhaps worth mentioning in favour of epoxymastic is that marine quality epoxymastic which is designed to protect metal in a salt laden environment is much cheaper than POR 15. I guess because it is a much higher volume market. 
Jotun epoxymastic specifically formulated to protect ships hulls is around £70 for 5L compared to around £50 for a Litre of POR 15. This is what I used on my chassis and the only rust in 6 years of all year driving is where I didn’t paint it:-)

no connection with Jotun by the way..

tim

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58 minutes ago, Richard Pope said:

Oh. Everyone says ster clear of galvanising as it weighs a ton and traps rust inside the members.

Rubbish and David thought you would know what to use in your industry anyway I used the same as the concrete industry and ten years plus still looks like new 

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1 hour ago, ntc said:

Rubbish and David thought you would know what to use in your industry anyway I used the same as the concrete industry and ten years plus still looks like new 

Hi Neil my stuff is normally subsea (Norsok 501 system 7) with nothing to chip it its around 500-600 microns but chips easy, thought this POR15 or the epoxymastic would be easy to apply and cheaper david

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3 hours ago, Richard Pope said:

Oh. Everyone says ster clear of galvanising as it weighs a ton and traps rust inside the members.

Hot dip galvanising is used in civil and structural engineering, columns, beams, etc. it’s the industry standard.

No rust is trapped inside box section members, all predrilled so it flows inside, treating within the box sections.

Edited by Peter V W
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I would be careful with hot dip galvanising as it involves heating the metal to 443 degrees C (according to the American Galvanizing Assoc) and this has been known to distort the chassis, especially if there has been welding work carried out.

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On 9/4/2021 at 5:03 PM, ntc said:

Rubbish and David thought you would know what to use in your industry anyway I used the same as the concrete industry and ten years plus still looks like new 

I said that because I quotes from ‘How to Restore a TR5/250/6’ book page 67 says galvanising is not recommended …

  • Two men carry chassis to galvanising, four men carry it back.
  • Zinc builds up inside and outside members.
  • Pre-galvanising acids get trapped in box sections, folds and welds and many a treated chassis will rot from within.
  • The high temperature process can distort a chassis that was previously aligned.
  • Welding galvanised metal is toxic should repairs be required.
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42 minutes ago, Richard Pope said:

I said that because I quotes from ‘How to Restore a TR5/250/6’ book page 67 says galvanising is not recommended …

  • Two men carry chassis to galvanising, four men carry it back.
  • Zinc builds up inside and outside members.
  • Pre-galvanising acids get trapped in box sections, folds and welds and many a treated chassis will rot from within.
  • The high temperature process can distort a chassis that was previously aligned.
  • Welding galvanised metal is toxic should repairs be required.

I agree.. it was always interesting to me though that lotus Elan replacement chassis were galvanised. 

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I'd be pretty impressed if hot dip galvanising could double the weight of a chassis! Particularly as it's less dense than steel. Very diligent operator, and worthy of promotion to management, his/her performance being so poor! Really, all? Hot dip galvanising is the gold standard. There may be poor practitioners but caveat emptor.

John

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I have sent a fair bit of railing, fencing, steel frame off for hot-dip galvanising. Yes OK slight bit heavier but then, for fencing, no need to paint so weight probably the same. They will not take thin steel as it will warp in the heat and hollow sections need drain holes. Finished product always seems harder to drill and cut than pre-galv must be the heat. I did restore my deere tractor and sent the body panels off for electric galvanising and they came beautiful and shiny before the powder coat.

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OK, so last weekend I painted the chassis with POR15 Rust preventative paint and their POR15 Top Coat paint.

I used (virtually) a quart of POR15 Rust Preventative paint as a two-coat base followed by 1.5 pints two-coat Top Coat. I used 1” cheap paint brushes and some of their thinners plus a large artist’s brush for a couple of difficult to reach places such as a lip inside the turret. Plus, a box of gloves.

Originally my chassis had been needle gunned to remove surface rust and then I had used their Metal Prep phosphorous coating solution but there were still flakes of rust in the awkward places so I got the whole chassis sandblasted and sprayed with a (grey) zinc-phosphorous coating.

I had the chassis on two thigh high trestles’ and mounted the frame on four screws to avoid as much contact allowing paint to dry. I had originally considered hanging chassis from an engine hoist but not too stable as it would swing and difficult to get at underneath and turret members.

I used an airline and a vacuum cleaner to clear out sand from members but very surprisingly each time chassis was turned over, more sand came out onto the just painted surface. Ugh and minor but could not do anything.

Two people are required to turn over the cassis to get to the underneath members as in my view it is pretty impossible to paint from underneath especially the front turret area which was bad enough from the top anyway. Ideally a rotisserie is required.

It is probably impossible to reach inside some turret areas with a brush so I am thinking of using an aerosol to spray into these hidden areas and hope for the best – not ideal but what else?

The POR15 paint is thin and the first coat seems easy to spread well without runs not that one would see runs anyway. Once done, it seems a thin but well covered coat and easy to get everywhere and the metal’s dimples too - impressed. Second coat seemed to make the whole paint a thick covering which was surprising as we used exactly the same amount of paint so must have given two equal and thin coats. It looked very gloss and overall just a thick coating.

Followed with POR15 Top Coat and again thin paint in two thin coats. Very difficult to see where one had gone as all paint so gloss / wet looking so constantly noting what had been painted and what had not – systematic painting required.

As instructed, I used an old table spoon to decant paint into a butter / spread plastic carton. I suggest not putting in too much but topping up as the paint got thick whilst painting – three to four table spoons a time.

First coat of base POR15 took two people 2.75 hours including turning over. 30 mins break saw paint dry enough to start again so give or take 2.5 to 3 hours to dry between coats. Second cost of base coat took 1.5 hours (two people). Now 2-hour break saw it dry enough to start Top Coat with the first coat taking 1.5 hours (two people) finishing off with a final Top Coat taking 1.5 hours (two people) the next day. The Top Coat took 30 minutes to dry between coats. In short a full day and a half to do all this including preparation.

I’m impressed by the result and all in all it does look a pretty thick finish and now waiting for it to cure in a week or two. I previously spray painted a different (but new) chassis and it took much the same time – a day and a bit. I did more very thin coats and the final coating looked much thinner than this chassis and more professional. I would use a brush for a restored rusty chassis and spray for a new chassis.

 

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