trouble spraying clear
 

Hello all

Over here from the 48-60 group.

I am redoing my truck and am at the point of clear coat. All the other body work has gone well and I am learning as I go. I am no body guy, but am trying.

I sprayed clear the other day and I will give you the particulars for the day.

finish line gun, wide open product and fan. Using Acme ( a line of Martin Senour ) Acme Finish FC-740, FH-742 hardener (75-90 degrees ).. 4- 1 ratio There was no reducer listed for this application. Base coat/ clear coat system being used.

I had TREMENDOUS ORANGE PEEL, as well as some dry spots. the dry spots were not to many, but the orange peel was all over.

It was hot that day as well as humid. Painting in a shop, with a quazi paint booth. One section, (front of body ) came out fairly well. The other parts not so good.

Gun recommendation was 8-10 psi at the tip with the trigger pulled with 20psi coming in the gun. Spraying about 6-8 inches away from gun

I could not figure out what I was doing wrong.

Today I started the wet sand process and still have a ways to go. the panels are coming out ok, but I feel I have created a lot of extra work because of my inexperience.

Any help would be greatly appreciated.

As a after thought, and during the rest of the painting process, I am going to make up some panels to test my clear on. I do not have any old steel laying around.

What tip are you using? 1.3 advised. You mentioned fan and product wide open. Fan yes, product no. Dry area's blame on technique. High humidity is never a good time to paint. Clear gives me a fit simply due to not being able to see due to improper lighting and the fact I'm no pro either. I'm sure some of the pro's that actually do this for a living will along to assist.

Thank you gfw1985 Will check the tip size this morning.

Starting to make my practice panels up

Spraying any finish is a skill that gets better only with practice, practice practice. Of course your equipment and its configuration make a difference but still nothing replaces all that practice.

Test panels are great but start keeping a bit of a record, writing down not only the day's weather conditions but your air pressure along with the complete list of everything about your gun. Any external filters etc? If so include those too.

In this way you'll be able to repeat the set-up especially if you have a good result.

Lighting is also massively important----can't really paint well without seeing that wet edge.

Thank you JWA Will keep records

Was going to say some clears like 1.3 and some 1.4. Heat and humidity would postpone painting for me. Since I only have heat I won't go past 80 degrees. Also, I am pretty sure one can add reducer to any clear. I have used a high solids PPG type clear which can be hard to shoot but the mix is 4:1:1 so I can add reducer to suit the temperature to slow the flash off of the solvent so it has time to flow.

Thank you tbm3fan

Mike,, thanks for the info, I will add that to my list of do's and dont's

JimG

Agreed, I have never sprayed a clear w/o reducing.......although there are probably times it will work good, hot humid weather is not one of those times imho...

I am unfamiliar with this Acme product but the data sheet says to mix 4:1 with the hardener and no reducer so I have to go with the manufacturer's directions. Where I do have an issue is with the pressure at the tip...I shoot clearcoat with as high a pressure as I can handle, definitely no less than 20 psi. The higher the pressure, the better the atomization of the paint and the less orange peel. Dial up your air pressure and adjust your product delivery screw til you get a good flow coat (read no runs and no dry areas) and you should see some good results.

Yetiman and CharlieLed

Thanks for the help. Will do all of the above next time I get to play in the shop.

Another question, I may re-shoot some of the panels. How far do i have to sand or scuff the existing clear. And with what grit. I am going to see how it wetsands and buffs out, but I may have to re-do. No big deal. I NEED THE PRACTICE .

At present, I'm working on the inside of the body in the bed.
https://cimg6.ibsrv.net/gimg/www.for...da7ac36dd6.jpg


https://cimg7.ibsrv.net/gimg/www.for...72912312d0.jpg


https://cimg8.ibsrv.net/gimg/www.for...aaf6b53d21.jpg


https://cimg9.ibsrv.net/gimg/www.for...77255db13c.jpg

I would use 600 grit and just remove the orange peel and scuff good where it is smooth

Thanks yetiman

I gauge the grit of paper needed by texture of the finish...in most cases 600 is good but there have been a few occasions that it took 400. Since you are going to re-spray anyway, go with the grit that knocks it down quickest yet still is smooth enough to spray over. I invested in a Hutchins water bug last year, a little pricey but it sure does make short work of color sanding.

Jon Kosmoski, creator of House Of Kolor paints, uses a technique when he clear coats where he shoots two coats and lets it sit for 24 hrs. The next day he blocks the surface with 800 and then shoots a tack coat followed by two "flow" coats. A flow coat is one that uses approximately twice the reducer (might be difficult in your case but you could try reducing your clear), this technique results in an ultra smooth finish that in most case requires no color sanding/buffing. A little extra time/effort but compared to color sanding and buffing it's nothing.

Charlie Led,,

Thanks for the info. I may try to call Acme and ask them what if any reducer could be used in a case like this.


Cant wait to get back out there and try some different things. Maybe this week end, We'll see

Man I would love to use one of those things....(water bug). They look like they would make short work of the clear sanding. Since I only paint ever 10 yrs or so can't see myself investing in one........

I have even used 320 to take care of really heavy peel or a sag but you got to be careful and not burn through to the paint.........