Paint Question

I painted half of the fuselage today in red Delfleet. The paint didn't seem to flow out properly and came out with orange peel. It seems I forgot the thinner when I mixed the paint. My question is can I buff this out later if I leave it or is it best to sand it down and re-paint it? Do I need to sand it all the way down flat or just rough it up?

Wolf said:

I painted half of the fuselage today in red Delfleet. The paint didn't seem to flow out properly and came out with orange peel. It seems I forgot the thinner when I mixed the paint. My question is can I buff this out later if I leave it or is it best to sand it down and re-paint it? Do I need to sand it all the way down flat or just rough it up?

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Depends on how severe the orange peel is. Also, depends on how good you are with sandpaper and a buffer. Personally, I'd sand it flat and respray. My experience in trying to sand and buff a metal airplane is that you're almost guaranteed to sand or buff through the paint over a rivet or a skin edge.

One suggestion is before you squirt any paint on the airplane, spray some on something else - a scrap part, a piece of flashing, etc. to make sure the paint gun is working properly and the paint is flowing out correctly.

Sandpaper

Kyle:

I think you are right, I had pretty much decided to sand it tomorrow and re-paint it. I bought way too much paint so that is not an issue, just hate to lose a day. Thanks for the advice.

Jay

Hi Jay.....

...you can also get better results by wet sanding. Get some wet-or-dry 220 grit and a water hose, keeping the surface wet. The sandpaper will wear out before it clogs.

Best,

pierre smith said:

...you can also get better results by wet sanding. Get some wet-or-dry 220 grit and a water hose, keeping the surface wet. The sandpaper will wear out before it clogs.

Best,

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Pierre probably has more experience in this than I do, but 220 seems very coarse and would probably leave marks that would transfer through unless you apply a thick finish coat. I'd use 400 or higher grit. And, like Pierre said, wet sanding is the way to go.

I would wet sand with 400. In fact, I have a fair amount of experience doing that on an RV

Wolf said:

I painted half of the fuselage today in red Delfleet. The paint didn't seem to flow out properly and came out with orange peel. It seems I forgot the thinner when I mixed the paint. My question is can I buff this out later if I leave it or is it best to sand it down and re-paint it? Do I need to sand it all the way down flat or just rough it up?

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Two options, depending....

You can wet sand with 1500-2000 then compound with a foam pad, IF you have enough paint thickness to cut off perhaps one full coat....best bet is three coats, cut off one. And Kyle is right, you gotta be real careful about edges and rivets.



Even a good paint finish is improved with this process. I'm using 3M's Trizact system; 1500 grit Hookit disks on a soft pad followed by a buffer, foam pads, 3000 grit compound and a polishing compound:



You can sand the orange peel flat and shoot new paint. If a non-metallic, 400 grit is fine. If metallic or pearl, use 800 grit.

That's amazing Dan. It doesn't even look like paint. What kind of paint was it? I was under the impression that you couldn't buff polyurethane.


-Tom

https://buyat.ppg.com/refinishProdu...?BrandID=5d7b4ed7-f83a-4469-b68c-04551702a5df

DBC pearl base and DCU2021 clear. The 2021 tends to bead up along edges, but it cuts nice. Yes, it's a urethane.

I'm just learning how to use this line. Friend and and RV8 builder Bill Woods is really good with PPG and recommends a different clear, but I forgot what it was. Hey, Bill, you out there?

Wow.

Hi Dan

Can you please do into more detail about how you achieved that particular finish? Did you shoot it yourself? In a booth, garage or back yard? HLVP? What primer did you use? How many coats of base and clear? How big a difference is there between the last coat of clear and what the cutting polishing process achieves (as shown in the photos)?

Sorry for the newbie questions, but would love to know - that result is glorious! Can mere mortals achieve it too?

Nothing special Chris....routine body shop stuff. The pros don't spray a perfect finish every time. They cut and buff to get it right.

Here's the latest from 3M:

http://solutions.3m.com/wps/portal/...market/Products/Featured_Products/Perfect-It/

I really like the new 3M compounds you see in the video. Obviously they want to sell every product them make but you may not need them all, in particular on light colors. I'm using a 1500 Trizact disk, then going directly to a buffer with a white foam pad and 3000 compound, followed by a black foam pad for the machine polish.

I'm a used car dealer; this is what I buy for my detail shop....good buffer:

http://www.milwaukeetool.com/ProductDetail.aspx?ProductId=5455&CategoryName=SC:+Polishers

A wool pad might be a bit too aggressive given our rivet and panel edge issues. Speaking of edges, notice the practice of taping for protection.

Yes, I shot it myself, in my home shop, which I built to include a paint booth of sorts. Three coats of clear over enough base to cover.

Here's a "before" photo for comparison. Ok, but can be better. It can be much worse and you can still save it with sanding, if you have enough material on the surface.



Ugly sight...old man sweating and swearing, spraying wings today, 90F+ in the booth.

Dan - do you worry about rivets when using the 1500 or hasn't that been a factor in your experience? The video is enlightening but obviously the trunk of the car isn't as challenging.

I have a product called Norton Ice which from a process point of view appears to be very similar to 3M. However I was going to do the sanding the old fashion way with 2000 and a block. I think I like the disks better

Haven't used it yet as I'm waiting for a least 30 days of cure time.

Wings looking good!

My first step in the paint process has been to scuff the whole surface for tooth with a 400 grit stick-on sanding disk on a firm pad. Mostly I do it for tooth but sanding has two other benefits.

Obviously all rivet heads should be flat and flush; the sanding disk will show you any which are not. Sand, shave, or replace and they won't haunt you later.

Little dents or dings are highlighted on the first pass. Mark them with a dot of tape and come back to fill them.

Dan your paint job is superb. two thumbs up. I am assuming you are sanding and buffing and then applying clear coat last right?... Curious as I plan to start painting very soon.

miyu1975 said:

Dan your paint job is superb. two thumbs up. I am assuming you are sanding and buffing and then applying clear coat last right?... Curious as I plan to start painting very soon.

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Thank you.

When everything is going well there is no sanding or buffing until after the last coat of clear.

Need to fix a screwup in the base coat prior to clear? You can wet sand metallic or pearl base with 800, but you must then shoot more base before going to clear. I'm told you can wet sand a solid base with 600-800 and go directly to clear. Nothing sees the buffer until eveything is done.

Haven't used it yet as I'm waiting for a least 30 days of cure time.

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Ken, that seems to be a holdover belief from the good ole days. Most body shops seem to cut and buff at 24 hours, less if force-cured. Check the data sheet for your paint.

I highly recommend "cutting and buffing" your finish when painting is complete.

Give it a little time to fully cure before sanding and buffing. But if you are having large orange peal problems when you are spraying, check you mixture ratio, check the temprature rating for the reducer, and check your air preasure.

typically the last 2 numbers in the stock number for your reducer is he temprature rating.. example "XX885" depending on the brand the first digits will be different but the last 2 designate it as 85 degree. This will work from 80 to 95 degrees.

This is how it normally lays out right from the gun,


This is what it looks like after I buffed it (graphics are on now too)

This is the RV on Sam James front page. It is N267RV that i painted about 4 years ago.. just saw it last month and still looks great!

If you plan to ad another coat of clear to your wetsanded top coat.. DO NOT BUFF IT. It needs those micro fine scratches to bind the new clear to your cured and sanded clear below. The compound will cause adheasion problems and chemical reactions with the new clear, that will not buff out.. as it will not stick!

I sent PainterJohn a PM... Grady told me a year ago I would be up June 2010 and I still have not heard a word back. Oh well... there's a lot of great paint shops out there.

i got your pm(s) Rieley
thanks!

I need to fly over next week... PM Sent