Problems with synthetic enamel .

[Al Fanning]

I'm using some synthetic enamel on a Land Rover and i'm having problems with sagging ( i've painted alot of vehicles with various paint with no problems ) . I've used it before and have have a few issues with slight sagging , but for some reason i'm getting the same result on the same panels - where i've had a sag and wet sanded it out - back to the primer , and recoated it , it sags in the same place . ( obviously the original sag was a result of too much paint ) It's not the thinning , or pressure or gun speed as other panels done at the same time , many verticle , are all OK .
Is it best to take all the paint off and start again with primer ?

P.S I've rejoined the forum as i couldn't remember my password and my email had changed .

 

[ford34/2]

its quite easy to narrow it down,

Applying paint too thickly

• Applying paint in cold or humid weather
• Paint that is over-thinned
• spray painting with the wrong tip or the gun held too close to the surface
  • Paint is applied in excess of the specified instructions
    
  • Too much thinner has been added to the paint
  • The gun is held too close to the surface, the angle is wrong
• Stan

 

[Al Fanning]

Thanks for reply , paint applied at 20 degrees , thinned 5% , 2.0 tip ( as used successfully before ) , gun at same distance as the areas which have no problems . Always in the same place - curved top front edge of front wing , so wrong angle ?

 

[ford34/2]

It must be 25 years + since i used synthetic, its very old hat now, a one chance type of paint, I used to stand the tin with a loose lid in a bucket of boiling water and applied it Hot, any runs -- yes they can be sanded out, but can take weeks to harden and might still react with a new top coat, If you havent got one, get a spec sheet for the brand you are using. it can be benificial to use the correct synthetic undercoat, If I was spraying it now, I hope the customer was a farmer, or owner of plant and machinery, its not a lot of use for much else.-- Sorry my opinion only. I recall more thinners than 10%, but it was warmed up and helped a lot.

Stan

 

[colnerov]

It must be 25 years + since i used synthetic, its very old hat now, a one chance type of paint, I used to stand the tin with a loose lid in a bucket of boiling water and applied it Hot, any runs -- yes they can be sanded out, but can take weeks to harden and might still react with a new top coat, If you havent got one, get a spec sheet for the brand you are using. it can be benificial to use the correct synthetic undercoat, If I was spraying it now, I hope the customer was a farmer, or owner of plant and machinery, its not a lot of use for much else.-- Sorry my opinion only. I recall more thinners than 10%, but it was warmed up and helped a lot.

Stan

Hi, yes I remember the stuff, some people used to use household paint, We used to put it on last thing during the day and then go home so we didn't stir up too much dust, and it would still be a bit tender the following day. I seem to remember that you could get a hardener for it which helped no end with drying time. But I think the technique we adopted was a flash coat then one heavy coat and leave it, then deal with any defects later if at all. For us it was always a quick cheap respray for the impoverished.

Colin

 

[ford34/2]

Hi, yes I remember the stuff, some people used to use household paint, We used to put it on last thing during the day and then go home so we didn't stir up too much dust, and it would still be a bit tender the following day. I seem to remember that you could get a hardener for it which helped no end with drying time. But I think the technique we adopted was a flash coat then one heavy coat and leave it, then deal with any defects later if at all. For us it was always a quick cheap respray for the impoverished.

Man after my own Heart, I too did quick flash over resprays, any plant enamel colour you could name, and in the 70s there were probably hundreds of ""fleet" colours, I think I used pertol to thin and wash the gun. The most amazing thing was if you did the wheels silver, they thought it was a super job. With regards to preparation it was very forgiving in as much, if it was flat it covered well. Company I worked for got the use of my compressor, I got to use a realy big "garage" at nights, all free of charge, great days you scratch my back and I`ll scratch yours, I looked after our fleet free of charge, they bought the paint I supplied the labour, but it more than repayed with the free use of the garage
Fond memories. Most of my stuff came from Ellison Valdis, Marys Place in Walker.. a decent job was of course celly, Still got both lots of tins in the garage, once in a blue moon i do a bicycle for some deserving kid and I find some obscure colour from the 70s 80s.----retro I think they call it now
Stan

 

[the snooper]

are there any contours in the panel or swage lines, its easy to get sagging around these areas as the paint builds on the lines then eventually as It gathers mass from above sags, also synthetic flows out quite a lot when its on the panel so while you may think you don't have enough on the panel look again a minute later and it will have flowed out and should look better

just seen your second post curved wing top, without doubt too much paint on the top
also you state paint applied at 20 degrees is this temp or angle ?

you should keep the gun at 90 degrees to the surface of the panel

 

[500e]

Ahhh Valflash synthetic coach enamel, we to used to heat it up as well ford 32, we put the pot on a gas ring, if you left it to long pot also had a built in heater element.
Mainly used it on commercials especially those with wood bodies, it was a product that took no prisoners if you got it wrong it was ugly, our "Wallace" was a genius with it, having done his apprenticeship when they used brushes & sprayed lead filler.
I do remember if you had a run it could be days before you could rub it down & there was a fast thinners for it. (well sort of fast)

 

[Al Fanning]

Thanks for all the replies , in reply to " the Snooper " that was 20 degrees temp . I recoated the problem panels again yesterday after wet sanding after 48hrs , same problem , same place , but to a much lesser degree , more like swelling where the sag was - i think i'll give the 3 days and do it again . Many thanks , regards Al

 

[richie00boy]

2mm is a pretty big tip. People usually use that for high build primer. It does sound like too much paint being applied.

 

[graffian]

Man after my own Heart, I too did quick flash over resprays

We used PPG Speedcoat. Speedcoat came in three flavours, the one we used was £4.80 a litre, a litre would
paint a min. Once you get used to the stuff it gave a great gloss and finish, but it seems to flow all night and was
still tacky the next morning; get it wrong and all the paint would fall on the floor.

 

[500e]

Those old paints would produce a super finish If you got the hang of them & no dust or fly's
Did not take well to Tcut though