Spray painting paint choices

[cwr]

Hi all
Having read the excellent book ‘How (not) to paint a locomotive’ several times now, I’ve been full of enthusiasm to try out Trimite’s non-iso 2k, and spray on a couple of coats in close succession while turning the part. I phoned my local Trimite branch for a chat and was rather discouraged when the guy there told me that:
a) he still recommended an air fed mask for the non-iso 2k as it’s not that safe that you should use a non-air fed mask
b) the minimum order quantity of 5l and the cost per litre of colour £22.36 and black £10.50. Given I need primer, satin black, gloss black, and 2 colours, this quickly gets ridiculously expensive. I didn’t even bother to ask if that included VAT…

So, I phoned another local supplier that retails HMG paints. Much more positive response, largely giving me the answers I wanted to hear. They do a non-iso 2k, and say it’s OK to use a conventional non-air fed mask, and are happy to supply small quantities such as 0.5l. However, having chatted a bit, the guy recommended using the HMG C71 Speedline single pack Alkyd enamel paint instead of non-iso2k, saying it’s just as good and will work out cheaper than non-iso. He quoted me £12/l. Apparently it is touch dry in 2h and flashes off in about 5 to 10 min.

Does anyone have any experience of this HMG C71 Speedline, or thoughts on the above? Would be great to get a few more opinions. Thanks.

[bambuko]

"...single pack Alkyd enamel paint..." is the usual answer for the amateurs with no 2K facilities.
Horrible stuff - tried it once and hated it.
He is telling you porkie pies - it is definitely NOT "...just as good..."

May work for you - at £12/l, why don't you get a can and try spraying your tractor to see if you like it?

[92220]

Hi Bambuko.

I'm not sure I understand what you are saying. Are you saying single pack Alkyd enamel paint is horrible stuff, or the 2K paints are?

Just to clarify, long oil Alkyd enamels are all the standard solvent based model paints that can be thinned safely with white spirit/turps sub, such as Precision Paints, Railmatch Paints, Cherry Paints, Humbrol Paints, as well as Crown, Dulux, Johnson, and all the other solvent based decorative paints. 2K products are for professional use only, with suitable breathing apparatus. Anyone using 2K products without the proper, professional, breathing equipment is taking a very big risk with their health!!

CWR: Speedline will work OK but the HMG Coach Enamel is far better, and is available in small quantities. It can be brushed or sprayed. The advantage of Coach Enamel over other types of paints is that it dries and cures as hard as the paint on your car, but retains flexibility, so is far less prone to cracking due to expansion and contraction of boilers when heating and cooling.

Bob

[bambuko]

Apr 13, 2017 18:35:34 GMT 92220 said:

Hi Bambuko.

I'm not sure I understand what you are saying. Are you saying single pack Alkyd enamel paint is horrible stuff,...

Sorry, if I wasn't totally clear - yes 1K enamels (in my experience) are horrible in use, but YMMV

[oldnorton]

CW

I spray small jobs with 2K isocyanate but ONLY in a fume cupboard, and with a Gerson 9000E mask plus G03E A1B1 cartridges. Not 'legally certified' for isocyanates but they remove all organic vapours and a mask with cartridges is around £30 (see eBay). I mentioned it before on this forum here modeleng.proboards.com/thread/11926/smooth-hammerite. My local paint shop mixes litre tins of topcoat for around £20.

Norm

[cwr]

Hi folks. Thanks for the replies. I'll give my local supplier a call after Easter to see what they say about HMG C71 vs their coach enamel.

The last time I sprayed I used an enamel from Spencer Coatings, as it’s what my local motor factors had I didn’t at that stage do much in the way of research into the options. It was OK, happy enough but I don’t remember being particularly enamoured by it. That was on a petrol loco that I literally haven’t set eyes on in over 3 years due to any free time being spent on steam. Must drag it out into the daylight again... I wonder if the Spencer Coatings enamel is similar to the HMG offering?

Paul1979, is that the HMG C71 Speedline or their coach enamel you recommend?

Thanks
Chris

[chris vine]

Hi,

My one comment about paint is this: Before you go to all the trouble of priming, undercoat, top coat, lining transfers etc etc. you really want to know that the paints will all work together. It will be a disaster if one of the paints reacts with something from a different supplier.

The only way to ensure they all work together is to either know what you are doing, or get them all from the same place!!

The only real departure I made was in the etch primer as I had a load of difficulty with the single pack stuff for spraying from a gun. I only recommend the Trimite two pack because I found that it worked really well. Yes, you may have to buy slightly bigger quantities, but at least you know it is good stuff!

The other etch which i found was very good was the Acid #8 by U Pol - in spray cans. This is easy to obtain in car paint suppliers locally or maybe in Halfords. It goes on thicker than the Trimite 2 pack, so will cover details a bit more. (The Trimite dries to a very thin layer.)

If you do try using paints from different suppliers, it is worth trying them out on test pieces before you spend hours, days, months on the model itself...

With regards to masks, you need a good one. I never tried an air-fed mask, but if I was doing another engine, that is what I would get. However you would need to feed it from an oil-free compressor I think so that you don't get the oil mist to breathe!! (the oil-less ones are more or less the same price as the oily ones but are much better for painting use as the oil mist does not contaminate the paint. (I found this out the hard way of course!))

Hope this helps.
Chris.

[cwr]

Hi Chris, thanks for the advice and comments. I appreciate the potential risk of not using a single supplier for primer and top coats. Guess the question is; use the Trimite that is well proven and for our application, or play it safe compatibility wise and use HMG throughout. HMG also do a chromate etch primer which goes on as thin if not thinner than SAP3. Point noted about doing lots of test pieces whatever way I go. Incidentally, the Trimite guy said that SAP3 will only be available a for a few more months.

I asked HMG about their coach enamel, they say it’s very similar to the Speedline stuff but takes longer to cure. Also pointed out that the data sheets give a much lower temperature resistance for the coach enamel.

I’m veering towards going the air fed mask route and doing the best job I can, thus 2k. Under ‘normal’ circumstances I would be more eager, but with a house move on the cards and wife still on maternity this is maybe not the best time for buying new toys… More pondering and procrastinating needed...
Chris