Paint questions

[Kernite]

Lots
I'm painting a Land Rover bulkhead and the door posts (all off vehicle). I've got a thumper of compressor and an Iwata W400 gun and have not a clue what I am doing but have read lots of threads, watched videos but still have a few simple (stupid questions).
Rightly or wrongly I have used a mix of paints but not had any reaction problems.

Primer coat was a 2 part expoxy from Rustbuster.
Undercoat was a cellulose (Xylene based) paint provided by the guy who sold me the topcoat which is Airspeed 272 QD Polyurethane enamel

Its a land rover so no need for that perfect finish but unfortunately I'm a perfectionist but suspect I will have to live with the finish I am getting which is proving variable.

Questions
1. If I use a tack cloth - can I paint immediately or should I wipe over with another cloth with thinners (I feel the tack cloth can leave the surface slightly sticky although am now wiping very lightly)
2. Can I move straight from the undercoat to the top coat or should I let the undercoat dry over night - if I do this do I need to prep the surface with 320 grit.
3. Should I spray light coats and slowly build up (wet on wet) or try and lay down enough paint in one go to form a gloss finish without too much that it runs - I am finding that on the top coat I don't always get a glossy finish so go over again to build more paint but this does not always work. This afternoon I upped the amount of paint getting through the gun - and am running just below 40 psi. I get a lovely fan and even laydown but not always glossy which I suspect is not quite enough paint.
4. because the bulkhead has a lot of different angles and nooks and crannies I am getting overspray which feels rough. Should I allow to dry and rub off with scotchbrite before laying down another coat.
5. I keep reading about "clear" which I am assuming is a clear laquer. Do I need to finish with this?
6. I'm struggling on understanding timings, which I suspect is paint and temp dependent. Sometimes I allow 15 minutes between coats of the same type and other times I keep spraying over until I feel I have a reasonable finish or am having no visible effect.
7.I am also in places getting a fairly bumpy finish - not really orange peel more cobblestones.

Sorry for essay. Any thoughts comments will be much appreciated. can post pictures but suspect photos don't really show the imperfections in their full glory. I'm adding about 10% thinners to the paint.

 

[norsa]

Struth mate. where to start?
Ok so your top coat should go on top of your primer but I would dry it overnight and maybe give it a flat back with 800 wet or dry (some would use dry) or grey scotchbrite.
A tack cloth feels very sticky in the hand but is purpose designed to do the job. Unwrap it completely and give the surface a light wipe over and paint.
You wont need clear unless you are using metallic base coat.
Now im assuming what you have in its fancy name is what we know simply as synthetic.
Its been a long time since I sprayed any but think each coat should give you a fair gloss.
you may be going too fast with your gun. Try timing a one meter pass at one second in time @ 7" from surface, drop down 3 1/2" ie half the fan span and do the next pass right to left then left to right. etc etc.
Fiddly bits give them 2 quick passes then let them flash off (don't scotchbrite synthetic) ((ever))before doing the entire surface. (1 metre 1 sec)
Your cobble stones could be dust. wet the entire spray area to minimise dust and finally again from memory heat the paint up to at least hot to the touch not boiling just prior to spraying and maybe don't thin it but deffo no more than 5%.
Does that help?
Im not a synth specialist so anyone feel free to trample all over me if im wrong.
Nick

 

[the snooper]

I havnt sprayed synthetic for years but I never heated it so there are 2 methods available, its a little hard to advise over the net but the paint continues to flow once on the panel so don't get tempted to put to much on especially near to any ridges on the body where the paint can build up as one minute it looks ok the next its running.
also be aware if it is synthetic its very sticky and ends up well stuck to anything it lands on including your airways so make sure you wear a mask

 

[langy]

Just to add thinners is not an alternative for Panel Wipe !!!

Synthetic eh, you might just regret using that

 

[Kernite]

Thanks first for reading my garble (written late) and thanks Norsa for adding clarity. Blood drained from my face when I noted Langy mentioned I would regret using the paint as I have 5 litres and a whole long wheel based landy to paint. The paint guy I bough it from supplies the land rover restoration market so took his advice - did I take a wrong turn?

Yes I noticed it was sticky - the filters on my mask were clogged up at the end of the day.

Thanks for all the comments - the bit I find difficult is that I am effectively practicing on the finished item so mistakes are going to be there forever. Although the bulkhead will be hidden by fittings inside and grease and dirt in the engine bay - it will be the large body panels where I will want a smoother finish.

Have looked at the end result in the cold light of day. The A and B post have come out OK although not as glossy as I would like. Discovered more runs than I thought on the bulkhead and perhaps cobblestones was a slight exaggeration more like cellulite Anyway pictures show it all. I can probably live with the finish but could I flat and respray or just flat and polish - the bulkhead is all edges so flatting would be a bit of a b**gr.

Weather is warm and paint flowing apart from the paint lumps I had not noticed that splatted out (have to admit the paint is past its sell by date) the days are warm and still at the moment so dust not a problem just the flying bugs.

Will build on advice and now go and paint the other side. Hopefully improving my technique.

Cheers

 

[richie00boy]

What is your tip size? That is massive orange peel, you are putting too much on and/or it's not thinned well enough. This will also help your gloss level. Have you got the proper thinners? Cellulose thinners is not correct. Did the supplier tell you the thining ratio? I've used 20-25%, but it depends on the paint and nozzle to an extent.

The problem with enamels is that they take ages to dry properly and you can't flat and polish them.

The undercoat was a wasted step, epoxy primer just needed a scuff then you can paint on it.

As already said, trying to use thinners as panel wipe will end in disaster.

If you have a lot of fiddly bits consider getting a mini gun.

Good luck!

 

[norsa]

The heating process I believe is to thin the paint and then as it hits the cold panel will thicken so as to be less likely to run.I would suggest the orange peel may be in the substrate, (in your case the primer/undercoat). It ideally would need a guide coat and flat pre gloss. You will never flat and polish synth but once fully cured you could flat and refinish. Dust is stirred up by the action of the gun which acts like a syphon if you like. Bugs, tough one. Years ago I did a complete refinish on a white mk3 Escort. Looked lovelly and orft I went for the celebration fag (for our American friends smoke), upon my return 100thunder flies dragging their feet all over the place!!
Langy scares most people at some time or another so don't take any notice. To be fair though he is right. synthetic is considered the best coating for heavy machinery and plant, not for cars. You could always stick whats left on the bay of e and get some air dry celly for the outside but you wont be able to spray it over the synth.
Nick

 

[steveo3002]

looks like you painted over rough primer to me

id agree synthetic isnt the greatest idea ...more for rough farm machines and skips etc , it will be very alkward to rework if you need to flat any runs or future repair work

 

[Kernite]

Tip is 1.4 and have just gone on line and note that Iwata state pressure should be at 28 so maybe I am running at too much pressure so will come down a bit.

Thinned paint with 8% white spirit - I was advised 5-10% so could go more as the paint is a little old. Perhaps 15%? But note norsa says no more than 5%. This is an extract from the SDS.

Air assisted spray, air assisted airless spray - an addition of 10% - 15% by volume of 800/001 or 800/0013 Thinner may be required to achieve optimum atomisation viscosity. Atomising air pressure 40 - 60 PSI.
Airless spray - tip size 11 - 13 thou minimum. Atomising pressure 2000 psi. Thinning not normally required.
Airspeed 272 QD Polyurethane may also be applied ready for use or for electrostatic spray as required. May also be brushed.

But note psi conflicts with gun advice. I also don't know what the paint supplier did to the paint before selling on may be thinner than original.

Yes I have orange peel on the undercoat so may be a magnification with each new coat so will flat the side I'm just about to paint. I have to say that the pic is the worst bit of orange peel. There are some smooth runs but don't know what I did differently. It will be hidden under the dash panel so out of sight and out of mind.

The undercoat was provided on the understanding that I would be spraying over old paint which is blue (both dark and light) so the undercoat was to give me an even base coat for the limestone finish. So yes on reflection I did not need it for the bulkhead which started from shiny metal and the grey epoxy primer.

We could have a debate whether a Landy is a car or heavy machinery I will take your advice and switch to celly for the large aluminium body panels to make my life easier provided the colour matches. But a bit of a bgr if I can't overpaint the bulkhead with anything other that the enamel.

I have a mini spray gun, I read a thread comment posted by Langy many moons ago where he recommended them so will try that on the fiddly bits.

Thanks for all the comments and helpful advice

 

[steveo3002]

primer needs to be sanded dead smooth , so its perfect as any defects or peel will show up

 

[Kernite]

Other side done. Did a little better apart from the mother of all runs on one small panel
I spent more time on the set up before starting spraying proper. Eventually kept the pressure at 40. Added a little more thinner, but not much, adjusted the paint feed and my speed of travel. Less orange peel but not quite as glossy as I would have hoped.

2 supplemental questions.

I noticed around the edges of a couple of large openings in the panel and on a couple of right angled panels that I lost a bit of paint on the edge - I suspect the opening or edge changes the flow pattern or am I stopping the gun to early at the edge of the panel. I should perhaps also have blocked the holes. Is there a technique to avoid this. perhaps laying down a coat on the corner, letting it flash off and then doing the panels.

First time I have used tack cloth - how many times can I use them before chucking. For example on a small saloon would one panel wipe do all the panels?

Thanks

 

[langy]

The heating process I believe is to thin the paint and then as it hits the cold panel will thicken so as to be less likely to run.I would suggest the orange peel may be in the substrate, (in your case the primer/undercoat). It ideally would need a guide coat and flat pre gloss. You will never flat and polish synth but once fully cured you could flat and refinish. Dust is stirred up by the action of the gun which acts like a syphon if you like. Bugs, tough one. Years ago I did a complete refinish on a white mk3 Escort. Looked lovelly and orft I went for the celebration fag (for our American friends smoke), upon my return 100thunder flies dragging their feet all over the place!!
Langy scares most people at some time or another so don't take any notice. To be fair though he is right. synthetic is considered the best coating for heavy machinery and plant, not for cars. You could always stick whats left on the bay of e and get some air dry celly for the outside but you wont be able to spray it over the synth.
Nick

Not trying to scare anyone with the truth am I ???

 

[the snooper]

i note you used white spirit ? yet i see the spec sheet states 800/001 or 800/0013 Thinner and you say paint flowing apart from the paint lumps are you sure its just not mixing correctly with white spirit ? ive never used white spirit in any paint ive sprayed

 

[Kernite]

Hi snooper
The same thought crossed my mind but could not find out what 800/001 or 800/0013 Thinner is but the paint supplier chap wrote on the can at the time of purchase that I should thin with white spirit so unless he had an off day. It all seems to work apart from the guy behind the spray gun. It cures in about an hour and seems quite hard the next day. It also mixes with the white spirit.

 

[norsa]

Not trying to scare anyone with the truth am I ???

only when you tell them they have wasted good money on a product that their suppliers wrongly assured them was right Steve.

 

[langy]

only when you tell them they have wasted good money on a product that their suppliers wrongly assured them was right Steve.

Well thats true then

 

[Kernite]

I'd rather hear the truth from the experts. I'm a novice and each part of my rebuild is a learning curve, but working against that is the fact I am only ever likely to do this once so miss out on the wealth of experience that exists with people who have seen it, done it and perfected it. If I am spraying paint I don't have any feel for what should be happening other than the paint coming out and landing on a flat surface. Years of practice is something I can not hope to achieve so sites like this and the advice freely given is much appreciated by us novices, I know I won't hit perfection but I might improve. I can only read the other threads and marvel at the skills that people have and the mountains that get climbed.

Sadly I suspect I will have to continue with the enamel paint that I have as a different source could be a different colour and if I can't over paint what I have already done then I don't want to risk a two tone vehicle. I certainly don't want the cost of stripping the bulkhead back to bear metal and starting again.

That said the finish might not be blingy bright but boy it does look durable

Also I've got a garage full of stuff I probably should not have bought, 1 tin of expensive paint would not be the worst of them.

 

[steveo3002]

Sadly I suspect I will have to continue with the enamel paint that I have as a different source could be a different colour and if I can't over paint what I have already done then I don't want to risk a two tone vehicle. I certainly don't want the cost of stripping the bulkhead back to bear metal and starting again.

have a good think..stripping a bulkhead would be a easy task vs scraping it off the whole vehicle when its not good enough

as ive said other paints can be sanded /polished /repainted as you wish until its good enough , synthetic your stuck with it

will prob wash off with some thinners as its new

 

[Burdekin]

Correct me if I'm wrong but synthetic seems to be the paint of choice for landrovers. Maybe ask on a landrover forum what's the typical paint to use but you do seem to see a lot getting painted with synthetic paint, so maybe there is a reason. It's not as if the panels are straight and door gaps spot on, so a bit of a agricultural finish is probably appropriate.

 

[norsa]

Landrover don't finish their landy's in synth to my knowledge. I think its just a farming style. Its quick to spray on and gives a pretty good cover up with fair shine and as it doesn't ever dry, its more resistant to chips and scratches, same as plant but its considered more of a last tidy up before the scrapyard in the car refinishing business.