What's The Next Step?

Got the fenders color sanded and flattened out using a trouble light to expose any areas that I missed. According to what I've read, it's now time for some rubbing compound.

Do I use a cutting compound then progress to a finer compound, or do I just skip to the finer compound. I made the final color sanding pass with 1500 grit.

All the "how to" information that I've seen says to use a power polisher for the rubbing compound. I'm reluctant to spend the money on a polisher right now. I assume the polishing can be done by hand. After all, I am not polishing 50 sqare feet of fender.

Yes, I've color sanded and now need to bring the color back out. Just got back from a local auto supply store that has been very helpful to this rookie. They take the time to do this because the manager is keenly aware of how much tractor iron is out there (just in our Club alone!) and seems to be courting the business. Smart man.

Acting on their suggestion, I got some 3M Imperial Microfinishing Compound. I think this may be skipping right to the final grade of compound, but the dude said that it will work fine since I finished sanded with 1500. I told him I was going to do this by hand as I didn't want to buy a polisher right now. He winced a bit and suggested that this will take me more time and that I had better go with a more aggressive grit then go with the Microfinishing. I told him TIME is what I DO have, so I went with the Micro. Can't wait to get home and start on this!

You guys have been a great help. I want to get good at this painting gig. There are three of us brothers involved in this crazy tractor stuff. (Our late Father created a monster here, by golly!) The youngest bro' is a very good mechanic, Bill (posts as Ohio Bill on YT) is a great parts/pieces scrounger, and I guess I'll become the painter. Maybe I SHOULD practice polishing first on Bill's 400. He's so stinking mad at what he's experiencing with the engine rebuild that at this point wouldn't care if you shot .357 Mag holes in the block.

I assume you were talking about the Super H paint job over the weekend?

Went to work with the Microfinish by hand. Very tedious, but I expected that. Not thrilled with the results! The surface is baby-butt smooth, but the color is a bit dull with a hazy look to it. I went back over some areas. There was not much improvement. Am now thinking that a machine is in order here. Tried to rig a pad on my DA with it locked out to circular only. This was a joke. I am now considering getting a polisher with the appropriate pads. The auto parts store had no pads for a DA, and perhaps a DA doesn't have the torque required for this application. As you mentioned prior, maybe the enamel surface needs to be 'melted' like the urethane you talked about, only achievable thru the high-speed of a machine. Something else to consider is that I jumped to the Microfinish without using a heavy cut first. The Microfinish will probably work with a polisher expediting matters.

"Yuck-AE- Boy is he in for a surprise! Even with a hardener it doesn't harden for some time-think weeks not days. He can sand it-but until it really hardens up it will not buff up and then if he does get it to buff too soon-it will most likely die back--Stick with AU more durable lasts longer etc" I had asked him if AE will buff better than AU--it doesn't. Earlier you said something to the effect that AU was too complicated, or something to that effect. It isn't, it goes using the same procedure as AE (I not talking bc/cc, haven't tried that yet). If all you have done is the fenders, sand it off and either repaint with AE and forget about buffing, or use AU with the intention of buffing if you need to. If you can get your gun and yourself to get a smooth finish with either, you don't need to rub it out. My technique is not quite that good yet, so I want the option of color sanding and polishing. You can sand AU the next day, and buff it out, although I have heard it waiting a few days before the final buffing will result in fewer scratches (not mandatory). I believe that you have to machine buff to generate enough heat to melt the scratches. AU is quite simply put, a better paint. Follow the instructions EXACTLY on the spec sheet, and don't guess and try to modify anything until you have had some experience. Your other altenative is to do as my advisor says and wait several weeks before buffing. You can repaint with AU before that. I haven't priced it but I imagine that AU costs only $10-$20 more/ gallon that AE. The paint prep, primers, etc can be the same for both. I would also like the comments of other people reading this post, I'm no expert, and there is more than one way to do things. Rod(NH) says he doesn't color sand, I would like to hear from both Rod and Gene, and anyone else. Sorry for the long, rambling post.

Well, I am not as down on AE as the autobody shops currently are. But I am also not color-matching metallic paint on automobiles for pay. And yes, I really don't color sand and I haven't compounded anything for years so I can hardly give the best advice on it. However, I have rubbed out AE (with hardener - forget it without) years ago. I had painted one of my cars using Centari w/hardener. It was done outside in the afternoon and left outside in the evening. Big mistake. I learned the hard way not to leave fresh paint outside when there is a possibility of dew. The paint was dry to the touch OK before dark but in the morning most of the roof had lost all it's gloss and was just a haze. I didn't have an orange peel problem but I sure was upset over the haze. I used a rubbing compound on a bonnet driven by a 7" dia sander/grinder. Worked slick. Brought back the gloss and I never had any further problem with that car - held the gloss for several years until I got rid of it for other reasons. I can't remember how long it was prior to rubbing it out but is was only a couple of days or so. Certainly not weeks. A friend on mine and I did the same thing with his car (also Centari w/hard) when he a had a relatively minor orange peel problem. His was jet black and was difficult to get noticeable swirl marks out. A final power polish cured that. One problem we had with his car was slightly compounding through the black down to the primer in a couple of spots on the rain gutter ridge (got to be careful in such areas). Minor issue fixed with an artist's brush. Years ago with older materials, to be sure, but still AE and before AU was available. Actually the line between AE and AU is sometimes muddled, as with DuPont's Centari Ultra (AE field mixed as "AU"). And with PPG's earlier Delstar "Polyurethane Acrylic Enamel", normally an AE if used w/o the hardener. Semantics? Perhaps. I am not a chemist so can't address the actual chemical makeup of these but they are (were in the case of Delstar) excellent paints IMO.

When I painted one of my trucks a couple of years ago, the hood wound up with a little more orange peel than I like to see. Few will ever see the truck (unregistered plow vehicle) but I was not satisfied myself. The paint was Centari Ultra and I suppose I could have bothered with color sanding and buffing but I didn't want to go to the trouble and I certainly wanted the appearance to match the rest (which was not going to get "the treatment"). It was much easier for me to simply cut down the peel with 320 on an RO sander and reshoot the hood. Problem solved.

There seems to be a lot of discussion about color sanding and buffing paint nowadays, almost to the extent that it is considered necessary or desirable and is actually planned for in advance. Especially by beginners. I suspect that is somewhat due to the prevalent use of hvlp equipment and the fear of runs. HVLP is SLOW, at least compared with pressure feed non-hvlp and it is understandable that beginners can wind up not getting the paint on wet enough, resulting in poor flow out and orange peel. Orange peel is the result of improper application; either spraying technique, incorrect products for the conditions or unsatisfactory atomization (gun adjustment). While after-the-fact sanding and compounding can correct a peel condition (if the film build is enough), it really should not be relied upon as a crutch to support poor application techniques. Besides, color sanding and buffing tractor parts, with the possible exception of some flat areas, is next to impossible to do well anyway. It really is not a manual (by hand) operation. Here's my quote again: "it's a tractor not a mercedes" :o).

My recommendation is to always get your confidence up by spraying test panels in the vertical position. I do that still when I use a different paint that I am not used to. Only then will you get the feel for that fairly narrow line between wet enough for no orange peel but not too wet to result in runs. It's not hard. It just takes a little practice and confidence. Don't overthink this whole thing. You will screw up occasionally, as I did with my truck hood. Take it in stride. Sand it or scuff it and reshoot, providing you used a hardener. If not, complete stripping is probably called for, unfortunately. If you don't get it right the second time, you need more practice. Unless you are doing this stuff for others for big money or are into making your tractor win prizes at shows, I would forget about color sanding and buffing. BTW, buffing is necessary after color sanding to regain the gloss, so it's a time consuming two-step process. It should not necessary for a "good" paint job. Confidence comes with practice and will, for the most part, eliminate any need for post-paint work.

It's difficult to compare costs because all AE is not the same and neither is all AU. For example, DuPont Centari AE actually costs more than PPG OMNI AU as I recall.

FWIW.

Rod

I went and got some AU at lunch. Interestingly, it wasn't hardly more than the Centari AE. The AU can go over the AE OK he said. I'll shoot again. Maybe won't need to color sand, etc this time.

My technique isn't that good yet either so, like you, am relegated to color sanding. Your response was LONG, but very clear so don't apologize at all! You write well.

Well now that I've compounded one fender way too soon and the consequences of that will be paint die-back, it does indeed sound like I will have to repaint. To tell you the truth, I kind of figured I would have to do this because I was waiting to crash into that proverbial road side oak tree somewhere in this little project. I'll just get some AU at the Auto Parts Store. To save some face, I'll just tell them I'm experimenting on "something else"--a little on the job training you see.

In fact, I DO want to shoot them again. There were two distinct areas on each fender where the paint really laid down flat. The only thing I can conclude is that these areas received the most paint! I think I will get a good paint gun, too. Our weather is going to be sweet this weekend. Should allow for nice paint flow-out.

We'll keep trying and we might get good at this someday.