Paint spraying -Expert advice needed.

[Trundlebug]

I did Avocet outdoors with Epifanes 2-pack. I wouldn't be in a hurry to repeat the experience! First of all, (unless things have come on in the last few years) I don't think there are ANY mask filters that are suitable. Some are better than others, but I don't think any of them are regarded as "safe":

http://www.hse.gov.uk/mvr/bodyshop/isocyanates.htm

That said, these guys claim that they've not had any complaints...

http://www.ebay.co.uk/itm/Gerson-2K...Mask-NOT-AIR-FED-MASK-CAR-PAINT-/350690393436

I waited for a hot, dry and almost windless day in summer, and tried to get the paint on just before noon. Inevitably, a variety of bugs landed on the job. Best thing is NOT to try to pick them off. Leave them until the paint hardens and then you only have to polish their footprints out, rather than their whole bodies and / or the big finger mark you left while trying to pick them off! I tried a polythene tent round the boat but because it was over grass and foliage, the humidity inside the tent just shot up.

I used a small HVLP gun but wished I had a larger one because the "fan" from it was pretty small. I'd have got a better finish with bigger gun but I don't think the compressor I was using would have provided enough air to feed one.

I painted one side and was absolutely delighted by the lovely gloos, so I then went round to the other side and when I'd finished that, to my horror, I went back round the first side and saw that it had more runs than a test match special! Sick as the proverbial parrot, I could do nothing but wait for the runs to develop on the second side (which they did). I was surprised at how long after the paint went on that the runs appeared. I also discovered (once it had hardened) just how hard 2k paints are to sand! Eventually, I got the runs out and then (a week or so later) had another go, but this time I was so scared of getting more runs that I think I probably put it on too dry and too fast. These "mist coats" that everyone talks about seem to have eluded me. Several very thin coats, "dusted on", built up into something with a rather disappointing gloss.

It's not "awful", but it's certainly not as good as a professional job. Probably "only just" better than with a paint brush. It is, however, as hard as nails. This season, we've been on a mooring with a galvanised steel ring on top and in light airs, the boat just rubs slightly against the steel ring. I thought it had damaged the paint, but a quick rub with some buffing compound and all the marks disappeared.

Yep, my experience mirrors yours.
I resprayed a car once, when doing a full restoration (admittedly with cellulose not 2 pack).
I found that I had just started to get the hang of it as I was finishing the job...

My conclusion was that although it's certainly possible and many people have done it with great results, for me it takes quite a bit of practice to "get your hand in" and get the technique right. By the time I've got it right, the job's finished.
Whereas if I'd let a pro do it he is spraying all day every day so he will make a much better job of it.

I'd never try and put anyone off doing it themselves though, as I've seen some great results achieved by people who have never sprayed before.

And the small areas I have managed to spray well give enormous satisfaction.
It's just that the large areas I didn't manage to spray well required repeated sanding, rubbing back , respraying etc etc which give enormous frustration! Always in corners and creases which aren't easy to get to...

 

[[159032]]

As long as you use the proper mask and appropriate filters it is not a problem otherwise there would be no sprayers.

Acording to the link I posted and the HSE advice Avocet posted and many other sources all within Google-reach filters are no protection against isocyanates which can pass into the body through the skin or your eyes.
The only protection is a full coverall and an air-fed mask (using a separate compressor which is drawing it's air supply from outside the spraying area.
The effects are not gradual. You can pass out or die from one session if you have taken no precautions and are in a solvent heavy atmosphere.

A company I worked for developed a 2K elastomeric membrane spraying system. They did not know (no-one did at the time) that isocyanates were so dangerous.
Their operative in charge of the components in the back of the wagon (the components were mixed in-gun) suffered a heart-attack as a result of the operating conditions. He never worked again, but at least he did live.

 

[PCUK]

Yep, my experience mirrors yours.
I resprayed a car once, when doing a full restoration (admittedly with cellulose not 2 pack).
I found that I had just started to get the hang of it as I was finishing the job...

My conclusion was that although it's certainly possible and many people have done it with great results, for me it takes quite a bit of practice to "get your hand in" and get the technique right. By the time I've got it right, the job's finished.
Whereas if I'd let a pro do it he is spraying all day every day so he will make a much better job of it.

I'd never try and put anyone off doing it themselves though, as I've seen some great results achieved by people who have never sprayed before.

And the small areas I have managed to spray well give enormous satisfaction.
It's just that the large areas I didn't manage to spray well required repeated sanding, rubbing back , respraying etc etc which give enormous frustration! Always in corners and creases which aren't easy to get to...

I know what you are saying but spraying to me is more than just posh painting, it's one of my bucket list ambitions (along with Tig welding stainless).
>>>>>
As for the air fed respirator comment, it's just not true. Isocyanate filter respirators are readily available although they have a short working life and coveralls and gloves go without saying. As I've been spraying for a couple of years now on and off it would seem that my 3M and Sundstrom respirators are doing the job!

 

[PCUK]

Thread update! Finally found where I've been going wrong with my spraying. A fundamentally basic mistake that no one mentioned. Discovered it on You-Tube. Gun air pressure! The only way I could get the air pressure up to required setting of 22psi was to use the regulator on the gun. I now know that this was totally wrong as by doing this I was actually reducing the pressure at the air cap instead of increasing it. The regulator on the gun has to be set fully open and never touched again! The reason I had insufficient pressure was due to setting the compressor too low. With this sorted I can now adjust pressure on the air line regulator to give the proper setting at the air cap. That's the trouble when you don't know what you don't know. Let us spray!!!