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The rough texture is only in the clear coat. The gun is a magnum HVLP gravity feed with 1.4 tip. It isn’t an expensive 1 I paid about $30.00 for it.
When I think about it now it took much longer to empty the cup compared to previous times. I think I need to really increase the volume of clear coat going through the gun.
What about adding reducer? I can add .5 of a part.
please, re-read the post i did on setting the gun. then try a test piece with the standard mix and see if it's good. try to find a piece of metal to use as test piece. an old stove, refrigerator, whatever.Quote:
Originally Posted by Jimi
i almost guarantee you'll need reducer. i'd start with 5% and try it. i bet 10% will be the ticket though.
i haven't used that gun before, but i've used enough cheap guns to know that you can get an acceptable finish once you get it set up right. having experience helps a lot too. a good painter can use just about any gun and get a reasonable finish.
clear has a lot of solids in it, it's going to act completely different than base coat. you need to not be afraid to put enough on it to get a smooth finish. that's where the practice panel comes in.
Thank youQuote:
Originally Posted by Len
B marler I followed your directions on gun set up and results are much better. However since I added some reducer to the clear coat I have some runs that I will need to sand before last coat of clear.
Thanks to everyone but real strange situation with spray gun. Looking at the manual that shows are the parts to adjust the settings there is 1 part that isn’t in the diagram but it has 3 settings on the gun. I will show some pics to demonstrate.
i bet that third control is air. it looks like it's behind the air valve on the trigger to me. you'd have to check that by pulling the trigger and acting on the control to see if the air volume goes up and down.Quote:
Originally Posted by Jimi
i run any air control on the gun wide open. i use a real regulator with pressure gauge at the gun inlet. be sure to set the pressure with the trigger pulled completely.
after you sand the runs out, i'd put two more coats of clear on. be sure to allow a good amount of time between coats. run the back of your finger against the tape that's right next to the paint area. it should feel pretty much dry before you put the next coat on. if you shoot too soon there will be too much wet material and it will run. better to let it sit longer. more experience will help time the coats. i like it to set up (flash off), but still be green enough for the new coat to melt in. when i was a smoker, i would use a cigarette as my timer. one of the long smokes (100 length i think) was the perfect amount of time. 10 to 12 minutes should do it as long as the temps are reasonable.
you say the results are much better. is it laying out nice and smooth now? it should have a glassy look to it. if that's what you have, then you need only to work on speed, distance, and overlap. these things are second nature to an experienced painter, but you'll need to develop that skill over time. a practice panel will help you here. try a single pass. you should have a consistent pattern width the whole way, and a nice smooth finish. if there's a dusty look you're probably too far away or too fast. if it looks kind of wavy or runs, you're probably too slow or too close. it should probably take about a second per foot of travel. so three to four seconds to do a pass on a fender. (that's just a guesstimate, every gun is different, but i think that one is a little slow.) with that gun i bet you'll get about a 6 inch wide pattern. your overlap will need to be enough so that you don't notice any difference in surface texture from one pass to the next, and you get a consistent film build. i don't really know how much i overlap, i just go by surface finish.
if you overlap 50% you'll essentially be double coating the surface. think about that a second and use that information to help you adjust your technique.
generally speaking, you only put paint on the panel after you verify that it's going to be ok. there's no sense in putting paint on if you have to sand it all back off again.
take notes of what you did. how you mixed, how many coats, air pressure, etc. it will come in handy later.
Thank you for the continued advise. I will show some photos of my situation. I have some runs around the wheel and on the sides of the box. I have some areas on the door where it is as smooth as glass but then 1 foot away on the same panel with the same setting on the gun it is rough like orange parcel texture. I have a valve on the gun so I can adjust pressure as the air enters the gun. I will open the valve on the gun you believe is for the air setting wide open and continue to rely on the gage on the hose at the gun after my moisture filter. Please see the pics. I think at this point it is probably speed distance issues. Need to be consistent
Attachment 32043Attachment 32044Attachment 32045Attachment 32046
that looks like either the product was too thick, the gun was set with too low pressure, spray from too far away. probably a combination of one or more things. take the time to figure out what the paint mix and gun settings need to be so the paint atomizes well. do a test pattern with thinner, and do one with mixed paint. they should be pretty similar if the paint is mixed right.
a test pattern like that is done by simply holding the gun still and pull the trigger back fully for a second and releasing. ideally the pattern should be cigar shaped. if not, there's a problem with the gun or the paint mix.
OK I will try that, I have wet sanded the runs out but the temp is 15 deg C so too cold to apply clear as I am outside in my carport.
What is the best way to paint the difficult areas where you are really reaching? For example my roof, I stand in the truck box with my knees against back window and start by spraying the area at the front left right but am really reaching. After it dries I look at the texture/finish and the part where I am reaching doesn't look as good as the section at the back of the roof since I am not reaching. Same goes with hood I am reaching and it is not the same through the panel. How is the best way to paint the hood that is still on the truck? I do 1 coat standing at the front like I would be if the hood was up and I was checking the oil. I am reaching to get to the area of hood below windshield, then I apply the next coat the other direction standing at the front fender and spraying from the middle back to me left right, go to other front fender and do the same left right.
my clear coat mix is 4 parts clear, 1 part hardener, .5 parts reducer for outside temp. I use a small cup to measure the parts, then blend all together in a larger very clean yogurt container, stirring very well then strain trough filter into gun cup.
I have several movable platforms made up that range from (2 ea.) 12x48 with a 6" height and 12x48 with an 8" and 10" height to give me reach over hood and top. If you cannot observe the surface when material is being applied it isn't going to go well all the time. I actually do a mock up spray with gun and hose attached to blow the surface off before I hit the vehicle with product as this tells me which platform to use and if my visibility for pattern and lighting is correct. You have to be able to observe the product hitting the surface, no exceptions in my opinion. I personally hit these surfaces side to side i.e., start hood from drivers side fender to just over mid section, work the front of vehicle and then walk around to passenger side and start from mid section to fender.Quote:
Originally Posted by Jimi
i use a small rolling scaffold similar to this one.
https://www.amazon.com/Metaltech-Min...2232238&sr=8-6
it's super handy and folds up when not in use.
OK it seems like standing at a door on a platform to spray roof left right then the same method on other side.
Also painting hood from feder spraying left right.
Spray back and forth starting at the side and extending to the center then go to the other side and continue by spraying from the center to the side and do the same on the hood.Quote:
Originally Posted by Jimi
Thank you for the information.
I made a platform and it worked great. How long does it take for the clear coat to get hard? I used PPG Shop-line 4 parts clear 1part hardener and added .5 part reducer.
In a container I have some dried CC that has hardener mixed in and I can pull it out of container and it is soft and flexible.
On the CC I use this is a copy paste from TDS for PPG DCU2021Quote:
Originally Posted by Jimi
Flash Time: 10–15 min. with DCX hardeners 5–10 minutes with DFX11
Dry Times 70°F (21°C): DCX8 DCX9 DCX61 DFX11
Dust Free: 60–70min. 80 min. 50 min. 10–15 min.
Tack Free: 21/2 –3 hrs. 23/4 –31/2 hrs. 2–21/2 hrs. 45–60 min.
Tape Time: 5–6 hrs. 6 hrs. 6 hrs. 10 hrs.
Air Dry: 16 hrs. 70°F (21°C)
Force Dry: Purge: 0–5 min.
Bake: DCX hardener: 30 min. at 140°F (60°C)
DFX11: 15–30 min. at 120–140°F (49°C–60°C)
I personally let the vehicle sit for 48 hours before touching. Although on several occasions I have shot some of my car buddies projects that were loaded and trailered after 5 or 6 hours. Makes me nervous when that happens. It really depends on your exact product info. I would check your TDS
Thank you
I am dealing with lower temperatures. During the day it gets as high as 21 deg C. During the night it decreases to about 12 deg C. I will start gentle reassembly tomorrow afternoon as I believe I am finished with clear coat.
I will post pictures after I finish.
that's normal. any thick section will remain rubbery for a very long time. that's one of the good qualities of urethane paint. it doesn't get brittle so it can stretch and not crack like lacquer as it ages and body panels expand and contract with heat. i have some little pucks of paint that are years old and are still pliable.Quote:
Originally Posted by Jimi
