die back
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try the dc98 I think you’ll like it for bigger jobs :pcorn:
ya dc92 is very drippy, not a bad clear if ya get used to spraying it. I’ve got a 5 gallon pail I’m slowly working threw, like it for completes though. The worst is when you bake it, it seems to increase the chance of runs drastically. I ignore the bake immediately for best results on this clear and give it 15 mins to set up. Far from a production clear.
i wish i knew what ya’ll were talkin about.:whistle: i only used dcu, and dc clears for so long. i don’t get to play with other brands, unless it’s ppg econo lines.:S
i did like dcu2082 clear. cured about in a hr or so. but they took that and my dch70 hardner from me when we switched to water.:cens
how ever i do like omni’s mc161 clear. the rep belives it’s the old dcu2001.:kofeeyou guys gotta remember that i dont do any production style work so i was just curious what normal procedure is for most of you. i will say this that with a 10 or even 30 minute flash you are going to be trapping some type of solvents and there is going to be some type of shrinkage. probably just acceptable amounts of for collision type work. now doing show work where there is a sanded and buffed finish you will easily see it down the road. for me, i always try and wait a minimum of 4 hours, preferably overnight. for all the solvents to come out it takes a minimum of 12-18 hours or so. i do realize that if any of you guys did that your shop would easily go bankrupt!!
Although I don’t agree with waiting as long as you do Jim you are absolutely correct.If you think about production painting sometimes you have to use sealer, a wet bed for your blend panel,3 coats of base,then bang on 2 coats of clear.That is alot of trapped solvent that can either cause dieback,delamination or solvent pop.When I used solvent base I would use slow reducer on everything.In our downdraft booths we have lots of airflow and it would flash off the same as fast reducer.Fast reducer in basecoat can cause your base to skin over slightly and cause some problems.I would let my sealer flash minimum 20-30mins,base 30mins,before clear.On a complete I would wait minimum an hour before clear.If you are turning off your booth I can see having to wait overnight or 4hrs,but if you have airflow and heat while the booth is running that is unessesary to wait that long.We also do show cars at my shop,not just a splash and dash crash shop.There is always something else to do out in the shop while you are waiting for a coat of whatever to flash in the booth,masking,prepping etc.
[quote=”Jayson M” post=15205]Although I don’t agree with waiting as long as you do Jim you are absolutely correct.If you think about production painting sometimes you have to use sealer, a wet bed for your blend panel,3 coats of base,then bang on 2 coats of clear.That is alot of trapped solvent that can either cause dieback,delamination or solvent pop.When I used solvent base I would use slow reducer on everything.In our downdraft booths we have lots of airflow and it would flash off the same as fast reducer.Fast reducer in basecoat can cause your base to skin over slightly and cause some problems.I would let my sealer flash minimum 20-30mins,base 30mins,before clear.On a complete I would wait minimum an hour before clear.If you are turning off your booth I can see having to wait overnight or 4hrs,but if you have airflow and heat while the booth is running that is unessesary to wait that long.We also do show cars at my shop,not just a splash and dash crash shop.There is always something else to do out in the shop while you are waiting for a coat of whatever to flash in the booth,masking,prepping etc.[/quote]
You said much of what I was thinking. When spraying solvent in the heated down draft I always used slower products (unless it was a very very small area/part). Too many advantages not to use the slow solvent. Even for spot repairs it works very well. Generally I would follow longer flash times between sealer and base as well as between coats of base. Before clearing I would allow a flash time appropriate to the number of coats (ie: 2 coats of black base, no sealer 20 minutes before clear…tri-stages I would wait at least 1 hour). Longest I have ever waited before clearing is close to 4 hours (on a large 2-tone job).
Now the water is a different story, far fewer problems (at least for me).
Yes for the guys that think water is crap there are no dieback issues and after 15mins you can hammer on your clear and walk away and not worry about the old problems.
Flash Times
I’m not in a booth but I have a pull fan in the bay.
I have learned that if I wait 15-20 min before my second coat of clear my runs and solvent pop (pop is rare for me) has become practically non-existent. I hammer the base after 15 minutes but I have become more patient and usually wait 20 min to an hour or so before rushing my clear over base coat…..like jason said there is always something else to do. :pcorn:ppg recomends a min. of 15 mins. before clearing, and before i used a downdraft booth, i waited 15-20 min. in between coats of clear. now i’m down to 3-5 mins. on the fast clear and 5-7 min. on the med. fast clear. 10 mins. on the slow stuff.
I’m on PPG Deltron Global, and am waiting at least 10 mins between base coats, and a minimum of 15 min before clear, but usually longer (around 45 min).
10 min before clear is pushing it. I have heard of other painters doing it, but I wouldn’t like to risk it (for the sake of 5-10 minutes).
During this past winter, I had a lot off issues with runs in the clear (on the second coat). I had my booth temp at 22-26 degrees C, but what I found out was that my panel temperature was much cooler than anticipated.
To solve the issue, in cold weather, I ended up waiting 30 mins between coats of clear, and invested in a handheld infra-red thermometer that I use to read the panel temp (got it on Ebay for $50 and is excellent!). Also works well when needing to ascertain the panel temp when IR curing fillers – especially for plastic parts that can easily melt/distort if they get too hot.
Keep in mind that the panel temps in the booth will be several degrees cooler on the bottom of the car as comared to the sail panel and the roof. I also bring my clear (sealed in containers, not activated) into the booth when I first start laying base so it comes up to booth temperature. That, of I’ll heat the clearcoat container in a bucket of 75 degree warm water (yep, I use the thermometer to check that temp too!).
Cheers,
Sime[quote=”Paintwerks” post=15214]I’m on PPG Deltron Global, and am waiting at least 10 mins between base coats, and a minimum of 15 min before clear, but usually longer (around 45 min).
10 min before clear is pushing it. I have heard of other painters doing it, but I wouldn’t like to risk it (for the sake of 5-10 minutes).
During this past winter, I had a lot off issues with runs in the clear (on the second coat). I had my booth temp at 22-26 degrees C, but what I found out was that my panel temperature was much cooler than anticipated.
To solve the issue, in cold weather, I ended up waiting 30 mins between coats of clear, and invested in a handheld infra-red thermometer that I use to read the panel temp (got it on Ebay for $50 and is excellent!). Also works well when needing to ascertain the panel temp when IR curing fillers – especially for plastic parts that can easily melt/distort if they get too hot.
Keep in mind that the panel temps in the booth will be several degrees cooler on the bottom of the car as comared to the sail panel and the roof. I also bring my clear (sealed in containers, not activated) into the booth when I first start laying base so it comes up to booth temperature. That, of I’ll heat the clearcoat container in a bucket of 75 degree warm water (yep, I use the thermometer to check that temp too!).
Cheers,
Sime[/quote]45 mins thats pretty long what do your data sheets state, the norm is usually 20-25 tops, but i supose it depends on how wet you lay your base and how much air movement your booth has.
i would be a little concerned at leaving my base for 45 mins, during the winter i keep my clear above the heater in the mixing room, make’s a big diference.
Also when metal temp is low during the winter i may pre heat the car in booth, yea the winter months are pita where vehicle body repairs are concerned cost me twice as much for gas compared to the summer months.
[b]spies data sheet 10-15 mins flash off recomended.[/b]
http://pc.dupont.com/dpc/en/US/html/visitor/common/pdfs/b/product/sph/SpiesHecker/293_07.pdfyou can do like i do with the clear, i keep the clear and hardners in the corner of the booth where it’s not so hot. i agree with the panels being a lot cooler, and had the car be cooler then the temp in the booth. there’s nothing like getting runs first thing in the morning. i also thought of buying a temp gun to montior the heat in the booth. i normally get a 30 degree drop form the booth roof to the top of the car, when bakeing.
i don’t know if your useing water, but i was told if you ir the clear you have to ir the water base too. but they never told us why.You know jason brought something good up concerning waterborne. For those of you that use it, what happens if you clear that stuff too early. It is water so what if there is a little dampness left in the base and you clear it? I would imagine you need to be real carefull with not trapping water under clear?
As for solvent base, tech sheets are written for production shops. Because it says 15-20 minutes doesnt mean you gotta get clear on it in that amount of time. Most every job i do unless its a single color will sit in base for weeks before clear while we are doing artwork. Once done we just clear it. Thats pretty much the norm across the board with any custom painting. Recoat windows go out the window and after years and years of paintjobs i can say atleast with the systems have used recoat windows are a bunch of bs. Probably just another thing a paint company can use to get out of a warranty.
i was told with water you wait 15 mins. also. i have gotten on it too fast. the only thing that happen was die back.
[quote=”lild” post=15237]i was told with water you wait 15 mins. also. i have gotten on it too fast. the only thing that happen was die back.[/quote]
really wheres the water go then??
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