SW G60 P2 Help

I need some advice from the group.

1. What is an appropriate clean up for the Sherwin-Williams primer. Mineral spirits does not work well with this as it causes it to clot up

2. I am having basically NO luck applying this stuff. I have the HF HPLV gun, and I found a good set of instruction on this form that describe how to set it up. I have tried that and it hasn't worked all that well for me. All is seem to get is spattering on the parts.

I also have a touch up gun that I get a little better results with.

I have used the duplicolor rattle cans, and get great results. I was hoping to get the same type of results with the PPG, but so far all I am getting is ugly parts.

My parts prep consists of scuffing the parts, then wiping down with acetone to remove any oils, and dust from the scotch brite.

Any advice would be appreciated.

Thanks in advance.

i would think laquer thinner would work well for this and most epoxies. your getting a reaction with the mineral spirits. mineral spirits are for thinning oil base paints like rustoleum and the like and to pre-clean surfaces to remove contaminants. most all other automotive type paints will clean up with laquer thinner and if that isnt strong enough then use mek.

sounds like your primer is to thick or air pressure is too low... thin it some. it should run off of a paintstick and stop dripping in about 5-10 seconds. or you can get a zahn(? )cup to check the viscosity.

as far as air pressure is concerned i put a gauge inline at the gun to get the air pressure set at my wall mounted regulator to what the manufacturer of the paint reccomends then remove the gauge. should be 40-50 psi for the gun you have. a fluid tip larger than 1.4 is best but it will work with a 1.4 just a bit slower.
i have seen as much as a 20 psi drop from the wall to the gun.....i need a larger diameter hose.

Is the P60G2 an Epoxie? It is called an Industrial Wash Primer.

There is very little information online about this product.

Would I be better off going with an Akzo or something like that.

I don't know if I CAN thin it any further. Should I get a different tip for my HPLV gun.

BrentHumphreys said:

Is the P60G2 an Epoxie? It is called an Industrial Wash Primer.

There is very little information online about this product.

Would I be better off going with an Akzo or something like that.

I don't know if I CAN thin it any further. Should I get a different tip for my HPLV gun.

Click to expand...

http://www.google.com/search?hl=en&rlz=1T4GGLR_enUS238US239&q=P60G2&btnG=Search

i found the above pdf to say reduce with their reducer R7K44 to 150% and to clean up with laquer thinner as i suspected..it is not an epoxy primer and by their own admission is not and effective corrosion preventive measure. that said i would reccomend the akzo or PPG's dplf 40 or Nason's fulpoxy..the two can be applied over properly cleaned alu but i did the full etch and alodine method..you can skip the alodine. i would not skip the etch. and yes if you cant thin it any more you likely need a larger fluid tip. i have the same gun you mention and it sprays akzo, dplf, ful poxy, and k38 well....the k 38 is very thick BTW so you may need to insure your gun is clean and you are getting sufficient air pressure. try running your regulator to 50-55 psi if your using a 3/8 air hose and see if that helps.

it should be noted that some of these primers ar very nasty and the gun MUST be partially disassembled to clean them..(removeing the fluid tip and using your touch up gun to spray mek or laquer thinner back through the passage.)especially the k36 and k38. that stuff will not come out of the fluid passage no matter how much thinner/reducer you spay through the gun in its assembled configuration. if it dries in there you will have to clean it with paint stripper. which tends to remove HF's purple coating
YMMV

• P60G2 is not intended for use over
adequate chemical treatments on
steel, galvanized steel, or aluminum.
Using P60G2 over these chemical
treatments may result in loss of adhesion.
• Sanding or light mechanical abrading
of hard, smooth metallic surfaces,
such as stainless steel or chrome, improves
adhesion.
• Contains chromates
• Does not provide significant corrosion
protection.

i have sprayed sem self etch over etched material and it litterally blows of with very little effort...if you let is stand for a couple of days it will simply lift off and look like leaves laying on your part.

I have had pretty good success with this S/W product. But I only picked it because it was what Van's used on the QB kits, so I wanted to match it (although it is a slightly different color).

I use Aircraft Finishing System's Aluminum Etch/Cleaner as a prep, and it seems to work just fine. Then I mixed the P60 G 2 wash primer with the R7 K44 catalyst reducer exactly as it says on the can (get the math right!). I primarily use an el-cheapo touch-up spray gun from Harbor Freight (I think I paid $6.98 for it on sale, and bought three of them) with good results. I do make sure the 'paint booth', aka garage, is at or above 70 degrees F. when spraying. I have sprayed a little colder than that and it didn't seem to make any difference - still had good results.

I don't have a pressure gauge right at the gun, but I set the pressure out of the regulator (other end of the hose) at 40 psi static (no air flowing), and it drops about 3 psi or so when I pull the trigger. Now that I've done a lot of priming, I also listen to the gun and air and adjust accordingly. But I always end up with about 40 psi static pressure.

For clean-up, I use the S/W recommended laquor thinner, R7K 120. It works really well. And I would agree that you need to completely disassemble the gun for cleaning. The clean-up is never fun (actually, none of the priming is fun for me), and I'm sure it isn't especially safe. But anything in moderation can't kill you, right? OK, maybe not. But I wear protective equipment through the whole process.

Many parts of this whole airplane project is a big unknown for me, and priming was certainly one of them. I had not sprayed anything other than with a rattle can. But now I have it down and really encounter no issues when priming. It just takes a while to get the "paint booth" set up.

Also, it was recommended to me to have a dedicated air hose for only painting - so you know it is clean and you won't get any oils into your work. So I have done that, too.

I hope this helps.

Brent,

Just a lesson learned on the HF HVLP gun. I also have one and found that they had placed a lable over the vent hole on the top of the paint cup cover. Make sure this is open, otherwise you'll be sucking on a vacuum.

John Tierney
Salem, WI

I do have a similar problem I guess with the SW P60. Searching the forum this post seems to match my issue. Unfortunately it seems that there was no resolution on this. Below a picture on how the primer looks when I spray it with my HF spray gun. I use 1 part p60 with 1.5 parts r7k44. Air pressure from 15 to 55 psi doesn't seem to make a big difference. Ambient temp is currently about 62F. Any idea what else could be wrong?



Any idea is very much appreciated.

Uwe

pak99 said:

I do have a similar problem I guess with the SW P60. Searching the forum this post seems to match my issue. Unfortunately it seems that there was no resolution on this. Below a picture on how the primer looks when I spray it with my HF spray gun. I use 1 part p60 with 1.5 parts r7k44. Air pressure from 15 to 55 psi doesn't seem to make a big difference. Ambient temp is currently about 62F. Any idea what else could be wrong?

Any idea is very much appreciated.

Uwe

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That looks like what I am getting. I need to order another tip for the HF gun, then give it another shot.

Until then, I will be using rattle can.

don't let it sit in the pot!

I have been using the P60 with great results. The spatter you are getting is a common problem. I found the best solution is not to mix any more than your gun can hold and spray it right away. If you let it sit in the pot it will "skin" up and get "sputtery" Another words don't mix up a batch in a pot let it sit, spray part of the batch it and then come back dump the remainder in your gun. Also don't try changing the mix ratio. It never works and it won't cure right if you do.

I found the lowest pressure you can get a proper spray pattern works best. P60 dries very fast and high pressure can result in dry coats. Play with your gun spraying on some scrap each time you prime. You want a nice THIN translucent coat. If it is a soild dark green your putting it on way to thick. I use two very thin coats with great results.

I found Lacquer thinner works best for clean up. Buy a five gallon can of it from a local body shop supply house.

Make sure you have a very good respirator. I use a full mask type. Remember there is acid and chromate in P60 so you don't want to breath it!

PS I live in a humid area so a inline dryer of some type is a must.

I started out using the SW primer, then went to AKZO. The AKZO is just about the same price, so I couldn't really see much of an advantage when using the SW stuff.

Let me first say I have little experience spraying P60-G2, but, recall a number of threads where folks get better results mixing the primer with a 1:2 ratio as opposed to the 1:1.5 ratio.

Don't spray in the cold

I found that this stuff does not like to spray cold. It will "mottle" like the pics show. Make sure the paint and parts are at least 60 deg f.

wingtime said:

I have been using the P60 with great results. The spatter you are getting is a common problem. I found the best solution is not to mix any more than your gun can hold and spray it right away. If you let it sit in the pot it will "skin" up and get "sputtery" Another words don't mix up a batch in a pot let it sit, spray part of the batch it and then come back dump the remainder in your gun. Also don't try changing the mix ratio. It never works and it won't cure right if you do.

I found the lowest pressure you can get a proper spray pattern works best. P60 dries very fast and high pressure can result in dry coats. Play with your gun spraying on some scrap each time you prime. You want a nice THIN translucent coat. If it is a soild dark green your putting it on way to thick. I use two very thin coats with great results.

I found Lacquer thinner works best for clean up. Buy a five gallon can of it from a local body shop supply house.

Make sure you have a very good respirator. I use a full mask type. Remember there is acid and chromate in P60 so you don't want to breath it!

PS I live in a humid area so a inline dryer of some type is a must.

Click to expand...

I may be expecting better coverage than I should.

I am shooting as quickly as I can get it mixed and into the gun.

Many have said that 2:1 works better than the 1.5:1

I'll second the 1 to 2 mix. It was the only way I could get good results. I think it is a good product and you can see the results on my RV-9A web site. www.jimsairplanes.com
I am using a regular paint gun at around 35 PSI. Also ask for OEM pricing at Sherwin Williams. I did paint the interior of the rear fuselage with Dupont vari-prime and didn't like it at all. It is very soft and soaks up dirt and any oils that are on your hands.

pak99 said:

I do have a similar problem I guess with the SW P60. Searching the forum this post seems to match my issue. Unfortunately it seems that there was no resolution on this. Below a picture on how the primer looks when I spray it with my HF spray gun. I use 1 part p60 with 1.5 parts r7k44. Air pressure from 15 to 55 psi doesn't seem to make a big difference. Ambient temp is currently about 62F. Any idea what else could be wrong?

Any idea is very much appreciated.

Uwe

Click to expand...

I have used P60G2 for about 20 years.
The product thickness seems to very occasionally and sometimes needs to be reduced slightly more than specified on the can.
Mix up a small batch at 1.75 (reducer) : 1.0 Paint product and try it again. I remember one can I had that required a 2:1 ratio but it worked fine.
When it is mixed to the proper consistency it is quite watery and should be sprayed on just thick enough to make the surface look wet. It should dry to a light green tint color, thin enough to see sharpie pen marks through.

BrentHumphreys said:

I may be expecting better coverage than I should.

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If are getting "coverage" you are spraying it far to heavy. The instructions call for a dried film thickness of only about .004" thick. That's why that call it a "wash" primer.

Curious Question for Scott

rvbuilder2002 said:

If are getting "coverage" you are spraying it far to heavy. The instructions call for a dried film thickness of only about .004" thick. That's why that call it a "wash" primer.

Click to expand...

I used the product on my 6 and now I am using again on my 3. I use it as a final coat over Alclad parts, dont ask me why, and as a base etching coat for my raw parts with DP Epoxy primers on top. Works great.
I am curious though, the product data sheets do say that it provides "minimal" corrosion protection. Why does Van's use it at all on the QB's?

JonJay said:

I used the product on my 6 and now I am using again on my 3. I use it as a final coat over Alclad parts, dont ask me why, and as a base etching coat for my raw parts with DP Epoxy primers on top. Works great.
I am curious though, the product data sheets do say that it provides "minimal" corrosion protection. Why does Van's use it at all on the QB's?

Click to expand...

Kind of makes me wonder why you would be asking this question if you yourself have chosen to use it on two projects.

Here is the text from an artical published in teh RVator news letter a few years ago. It will hopefully answer your question.

Sherwin Williams P60G2 Primer Test
We do our best to avoid the ?Primer Wars? that tend to propagate through the RV builders community. Spend even a small amount of time in any of the on line news groups and it quickly becomes obvious that it is a very passionate subject. Even so...we thought the following might be of interest to some of our builders.
A few years ago (April 15, 2002) I decided to do a test to see what protection value the Sherwin Williams P60G2 Wash Primer has on bare Alclad aluminum. No attempt was made to use any science, so I guess we can call it a (Very!) unscientific test. Even so, I believe that it has provided some useful information.
The test sample is a .025 inch thick scrap piece of 2024 T3 Alclad aluminum. One third of it was cleaned and left bare. The middle third was cleaned and sprayed with a single light coat of P60G2 Self Etching Wash Primer. The final third was scuffed with a Scotch-brite pad, cleaned, and then sprayed with a light coat of P60G2.
The test sample was hung outside under a stairway of our building so that it was protected from the sun (U.V. light), and direct exposure to the 11 months of non stop rain that we get here in Oregon <Grin>.
Recently I removed a small portion of the primer from the end of the test piece to see what the condition of the aluminum was underneath the primer coating. After 3.5 years of outside exposure, the aluminum surface that was beneath the primer is still shiny new. The portion that had no primer has a light coating of surface corrosion.
What does this tell us? Well I guess the first thing it tells us is that unprotected Alclad aluminum will corrode. I believe that this test (as unscientific as it is) is probably a worst case situation compared to the exposure that bare aluminum gets in most aircraft. Vans Aircraft is located only about 60 miles from the Pacific coast as the crow fly?s, and areas of aircraft structure where skins are typically left bare are closed areas and do not get the same type of open air exposure that the test piece received. I have crawled around in the tail cones of many 35+ year old certificated aircraft built with unprimed Alclad skins, that had no more corrosion on their skins than the unprimed area of the test piece. The other thing it tells us is that an additional level of corrosion protection doesn?t require the use of an expensive five step process that meets some Mil-Spec. that most of us can?t understand, but is much more labor intensive to apply, and more dangerous to the environment and the people applying it.
At Van?s, we still believe that constructing an RV without adding any additional protection to the Alclad skin surfaces is a viable, lower cost / lower labor option. If you will be able to see crashing waves of an ocean coastline from the airport that your airplane will be based at...then it might be a good idea to add some additional protection.
We also believe that the product that we apply to the Quick Build Kits that we sell, is a good compromise in cost versus corrosion protection benefit. It affords the customer the added airplane value of additional corrosion protection on the entire airframe without a lot of additional cost.

Thanks Scott

rvbuilder2002 said:

Kind of makes me wonder why you would be asking this question if you yourself have chosen to use it on two projects.

[/I]

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uh...human nature to ask a question of Van's to get the answer that you already justified in your own mind to make yourself feel better

Thanks again.

rvbuilder2002 said:

I have used P60G2 for about 20 years.

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I'll go Scott one better. I've been using SW wash primer about 30 years. I've found that it works well on aluminum, fiberglass, and especially on magnesium. I was once contacted by Sherwin Williams about using it for corrosion protection. I asked them what they would recommend for the interior of aluminum aircraft. After about a month wait from their engineering group, they were unable to recommend anything better. I have used it on many airplanes and continue to do so.
And like Scott says, you don't need to "cover" with it. If you can tell it's there, you have enough.