help, orange peel in basecoat epic.

[djinuk]

Ok a quick background, ive painted a few bits in teh past with no issues.
Im using a new digital regulator on the gun, and the correct mixing ratio with a high quality thinner.


The story is below.



not the best day today, the mrs helped me out in painting the hardtop.

Masked up,

Applied high build primer, then a couple of areas blisteered up, i sanded these back and it all the way back through the original silver the hardtop once was. I filled these with top stop, reapplied high build , and flatted this all back to 800

I then applied basecoat black in a 2:1 ratio as per morleys, however no matter what i did this was going on with a terrible orange peel, air pressure was fine etc, to top it off, when i applied the basecoat , once again 2 areas of the roof had a blister, once again this is all the way back to the very original silver coat.

All i can think is that the original paint was cellulose and the thinners are reactivating it, although this is just a guess.

Plan is to flat all the orange peel back, dig out the blisters and filler the whole, and then go again with a 1:1 ratio on the basecoat. (although i did confirm with my friend who said morelys basecoats are 2:1 so im really not sure.

 

[the snooper]

it is either too thick or presure too low or a combination of both
as regards to your reactions if this keeps happening prep it and use some barcoat to isolate the full pannel then prime and paint

if you have used this paint before with the same gun and compressor with no problems then you must assume that your new regulator may be at fault as it is the only thing different

 

[Engineer1964]

As the Snooper says, You're putting your base coat on too thick/heavy. Apply thinner coats and add more coats for coverage.

 

[sprayerDrew]

What is your room tempreature as basecoat doesnt like going down on cold surfaces. Id also check your pressures and mixing ratios

 

[Chipper]

What type of paint is the hi-build?

 

[langy]

What is your room tempreature as basecoat doesnt like going down on cold surfaces. Id also check your pressures and mixing ratios

x 2

 

[djinuk]

pressure was 29psi, which is perfect for my devilbiss gun.. Ive used the same type of paint before , but about 6 months ago.

In the past all my basecoats have been 1:1 ratio, rather than the 2:1 i was told to mix this in. It was quite a cold surface. Ive ditched the air reg in favor for my old trusty.

I dont really want to prime the whole lot if i can help it, so i was going to barcoat just the lower leading edge where the blister developed, highbuild that area, flat it. Then go in again with teh same paint mix and the same air pressure but on the new reg and see how it goes on, If it still goes on thick im going to mix the basecoat to 1:1 ratio, and see if that helps.

 

[Chipper]

Whats the hi-build. In other words - if solvent-based the 1k base be causing it to react, or could be just cracking like 1k can.

Data sheets will tell you the mixing ratios.

 

[djinuk]

high build is 2k max meyer, although the hardener was a bit old and took some mixing.

Ive tried trying to find the standox basecoat datasheet but struggling.

 

[Chipper]

2k hardener has a shelf life, wonder if that's a cause of reaction. I just binned some, it went a bit strange when mixed, wasn't happy and then went very slightly yelllowy.

There was a handy post on here with a link to a page that listed a whole bunch of manufacturers data sheets, dunno if your one is in the list but maybe a search would find the post.
edit - Standox link - http://www.standox.co.uk/portal/en?page=2.4_Technical_Data_Sheets

 

[djinuk]

possibly, although it did mix in, ive done a search of the net and it dosent really seem to cause issues, also when i sanded the blisters back they seemed to go all teh way back to an original silver basecoat, so im guessin that was probably celulose and the thinners in the basecoat caused it to react.

Any idea if when you spray bar coat, do you have to flat it back or should it come out smooth enough to paint straight over ?

 

[Windy Miller]

possibly, although it did mix in, ive done a search of the net and it dosent really seem to cause issues, also when i sanded the blisters back they seemed to go all teh way back to an original silver basecoat, so im guessin that was probably celulose and the thinners in the basecoat caused it to react.

Any idea if when you spray bar coat, do you have to flat it back or should it come out smooth enough to paint straight over ?

DON'T flat the barcoat - just paint straight over the top

 

[djinuk]

will i have to prime over the barcoat ?, or just basecoat straight over the top

 

[the snooper]

when 2k activator goes off it forms tiny chrystals and if you use it in paint it looks like you have water contamination in the paint

 

[djinuk]

ah , wont have been that then, although i only use that hardner with the high build so that should be fine.

 

[Championship White]

In my experience the finish you get with barcoat is never good enough to spray a base-coat onto. Barcoat, prime, flat then paint.

 

[the snooper]

In my experience the finish you get with barcoat is never good enough to spray a base-coat onto. Barcoat, prime, flat then paint.

dont get you there at all
once you use barcoat you then use some high build and flat again ive never had any problems when ive had to use it

 

[Raf]

^^ i think he means the finish on the barcoat wont be flat enough to start painting base. he will, as suggested, need to prime, flat that then base.

think OP wanted to skip primer over barcoat.