Author Topic: Opinions on paint job (pictures included)  (Read 6654 times)

0 Members and 1 Guest are viewing this topic.

Offline drdreas

  • Enthusiast
  • **
  • Posts: 113
  • 77' CB750k
Opinions on paint job (pictures included)
« on: May 14, 2010, 08:42:14 PM »
I'm rebuilding a 77 CB750 custom and included is a paint job using Rustoleum general purpose black spray paint. I'm using black as a basecoat, stripes in off-white, and clearcoat using Spraymax 2k.

I stripped, primed, wet sanded, primed, shot several coats of black, masked, and shot the white. The problem I'm running into is when I wet sanded the black base coat. I wet sanded with 600 grit, water/soap mixture, and as soon as I started getting the surface smooth, the high spots that were sanded down began to discolor and look to be a mottled gray. It almost looks like I burned through to the primer, but I don't think this is the case bc I layed 4-5 coats of base, and I barely sanded.

Is this the look I should be expecting when I wet sand black, or is something wrong??

A friend of mine recommended that I respray the black and go right to clear without wet sanding. The problem with this is that when I spray the black, its almost impossible to get a consistent finish. Some spots are wet and shiny, some are dry. If I clear over this without sanding, will the different textures show through the clear?

Below are pics of the tank with a few spots sanded showing the discoloration:






Here is a pic of the rest of the tank before sanding, showing the inconsistency of the finish, some parts wet, some dry.


I'm afraid that because I have already masked and shot the white, that to reshoot the black, I would never be able to remask the white perfectly. Any ideas on how to do this?

Thanks

Offline BeSeeingYou

  • Old Timer
  • ******
  • Posts: 3,913
Re: Opinions on paint job (pictures included)
« Reply #1 on: May 14, 2010, 09:43:20 PM »
How long did you wait before you wet sanded? Was the paint fully cured?  Maybe the rattle can experts will chime in but I would question whether you can get a really good finish with a cheap general purpose paint.  It looks like there is some serious orange peel, could be your technique or just a cheap crappy nozzle laying down a poor pattern.  I have used paint like Duplicolor and have not had any problems and I think the nozzles lay down a better pattern too.
« Last Edit: May 14, 2010, 09:44:58 PM by srust58 »

Offline Stev-o

  • Ain't no
  • Really Old Timer ...
  • *******
  • Posts: 34,324
  • Central Texas
Re: Opinions on paint job (pictures included)
« Reply #2 on: May 15, 2010, 06:58:38 AM »
Also looks like not enough color - how many coats of black did you lay down?
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline turninwheels

  • Full Member
  • *
  • Posts: 84
Re: Opinions on paint job (pictures included)
« Reply #3 on: May 15, 2010, 07:00:33 AM »
hmm, by the looks of it was the paint cured enough, did it ball up when you wet sanded?
"high powered suicide machine."

Offline drdreas

  • Enthusiast
  • **
  • Posts: 113
  • 77' CB750k
Re: Opinions on paint job (pictures included)
« Reply #4 on: May 15, 2010, 08:36:54 AM »
I think it is possibly a bit of all the above. The black that I used was general purpose Rustoleum, and yeah the nozzle was very bad and made it hard to lay a good pattern. The white was duplicolor, with a much better nozzle and finish.

I waited 24 hrs before wet sanding, and it didnt seem to ball when sanded it, but the folks from rustoleum said discoloration may be due to it not being fully cured. I'll post pics more pics today, but I sanded more of the tank after letting it sit 4-5 days, and still got the same results, so I doubt curing is the issue.

Maybe I did lay too little color. I used pretty dry coats because I wanted to avoid runs, and even though i did 4-5 of them, could it be I'm just burning through?

So for damage control, whats the best option to fix this up without having to redo everyything, especially the stripes, which took forever. Can I respray the black? Should I get duplicolor black and respray the black areas with that?

Thanks

Offline wildcatmahone

  • Poseur
  • Hot Shot
  • ***
  • Posts: 320
Re: Opinions on paint job (pictures included)
« Reply #5 on: May 15, 2010, 09:21:49 AM »
#1: It appears as if your not laying enough of the black down and or the surface wasn't cleaned thoroughly between each painting session. Clean it twice and then clean it again prep is the key to a good finish. Should be smooth not blotchy and uneven for the most part. The "dry" and "wet" spots you see when the paint is DRY are simply where there is uneven coverage and paint buildup. 24 hours and the paint should be dry. Rustoleum will give you a sweet finish if you take care and apply it right. I hope you were wetsanding between coats and using progressively finer grit grades between each coat. 600 grit is pretty rough as far as wetsanding paint goes you wanna be up to about 1500 before you lay the clear. Make sure you have a clean nozzle and decent spray pattern test on some cardboard or whatever before you hit the tank and make sure you have really good lighting to see how much paint you are laying down. Any other tips I forgot right are at my old thread.

http://forums.sohc4.net/index.php?topic=36659.0

#2: When you wet sand gloss paint it will become dull and once you clear the gloss will come back up. The next step I would take would be to masking off the white and spraying more black to get a better buildup. That spraymax clear ain't cheap so I would make sure the base coat is where I want it. If that don't work other option is to start it over sand it all back down. Not what you want to hear but when you decided to paint your own tank you decided to take a learning curve and sometimes this is what happens.  Hope this helps and good luck.

Offline drdreas

  • Enthusiast
  • **
  • Posts: 113
  • 77' CB750k
Re: Opinions on paint job (pictures included)
« Reply #6 on: May 15, 2010, 09:27:29 AM »
thanks for the advice. Is there a big difference between the rustoleum professional and the general purpose? I guess Im leaning towards trying to mask off the white, and reaply the black. If I do that I figure I might as well use the professional if its better than the general purpose.

Also, what do you use to clean the paint with between coats? I was afraid of using alcohol based and have it eat the paint.

Thanks

Offline wildcatmahone

  • Poseur
  • Hot Shot
  • ***
  • Posts: 320
Re: Opinions on paint job (pictures included)
« Reply #7 on: May 15, 2010, 09:36:06 AM »
Rustoleum Pro appears to be an improved formula harder and dries quicker. To clean prep before painting go get a bottle of TSP paint prep and use some tack cloths to clean any remaining dust off the surface.

Offline drdreas

  • Enthusiast
  • **
  • Posts: 113
  • 77' CB750k
Re: Opinions on paint job (pictures included)
« Reply #8 on: May 15, 2010, 09:42:05 AM »
Ok, so its settled, I will respray the black. Not sure if I should go with duplicolor black, (the white went on with much less trouble than the rustoleum, or with black rustoleum pro.

The big question now is, is it possible to mask the white stripes so that I respray the black and it doesnt look terrible? Or should I just sand everything down and start from scratch?


Offline BeSeeingYou

  • Old Timer
  • ******
  • Posts: 3,913
Re: Opinions on paint job (pictures included)
« Reply #9 on: May 15, 2010, 11:56:16 AM »
How about just masking the wide stripe and then redoing the pinstripe with either pinstripe material or repainting.  Probably easier than trying to mask what is essentially two thin pinstripes.

Offline wildcatmahone

  • Poseur
  • Hot Shot
  • ***
  • Posts: 320
Re: Opinions on paint job (pictures included)
« Reply #10 on: May 15, 2010, 02:48:01 PM »
Nuthin personal but those pinstripe lines could be alot cleaner. What masking tape or you using blue or green should be the green for the sharpest line. I would just start over and take what you learned and do it right.

Offline drdreas

  • Enthusiast
  • **
  • Posts: 113
  • 77' CB750k
Re: Opinions on paint job (pictures included)
« Reply #11 on: May 15, 2010, 05:36:58 PM »
Thats a good point, Im not too happy with the pinstripes either. I used a 3m 1/8inch blue tape thats sort of stretchy for doing curves. When I removed the tape after 24 hours some parts created a clean line and some cracked into the line and created jagged edges.

What's the best way to prevent this, and why the green tape instead of the blue? I had trouble finding places that even had 1/8" striping tape. Auto parts stores didnt have it, auto body shops didnt, and neither did Sherwin Williams paint supply.

Thanks

Offline wildcatmahone

  • Poseur
  • Hot Shot
  • ***
  • Posts: 320
Re: Opinions on paint job (pictures included)
« Reply #12 on: May 15, 2010, 06:00:40 PM »
Yeh the blue is just general duty painters tape for house painters etc. The green is the high performance stuff that will hug curves and not allow the paint to bleed under or you can buy special vinyl pinstriping tape in as thin as 1/64" just google it. Good Luck.

Offline wildcatmahone

  • Poseur
  • Hot Shot
  • ***
  • Posts: 320
Re: Opinions on paint job (pictures included)
« Reply #13 on: May 15, 2010, 09:26:38 PM »
I agree was actually just at their website. One thing to mention dont use the Rusto clear as it is NOT fuelproof just a word of warning. Use the Spraymax 2 part.

Offline theofam

  • I'm cold, give me a
  • Hot Shot
  • ***
  • Posts: 598
  • Suffering from MDD - Mechanical Deficit Disorder
Re: Opinions on paint job (pictures included)
« Reply #14 on: May 15, 2010, 09:49:22 PM »
Wildcat,

You did the exact same thing I did when I was painting a buddy's fender and some of my parts a couple weeks ago - sprayed it too dry (dust coats).  Whether I was painting with a rattle can or a compressor/paint gun, I was rushing my strokes.  I couldn't sand out the "dust" to a point that it looked satisfactory.  If you clear over what you have now, it'll look bumpy/dusty.

I found that by slowing down my arm and spending more time on the paint stroke, I got better coverage and more of the mirror finish I was hoping for.  It all came down to pace.

I know you're concerned about runs, but a run or two is easier to sand out than trying to sand a dust coat smooth.  In fact, over at dotheton.com this link says you're rattle can painting correctly if you get runs!  http://www.dotheton.com/forum/index.php?topic=10993.0

Offline Old75_ratafe

  • CB750 Cave Spelunking
  • Expert
  • ****
  • Posts: 801
  • 1975 CB750K
Re: Opinions on paint job (pictures included)
« Reply #15 on: May 16, 2010, 12:07:02 AM »
One thing I don't think I have seen brought up is you are using regular rustolium right not the rust tough stuff right?  If that is the case have you mixed paint types because I believe the regular stuff is a oil base which means if you use anything else with it, it will not stick properly.  I know a buddy of mine had that issue with a car he rattle canned with rustolium looked ok and kept the rust at bay but he was told in order to have it repainted he would have to strip it to metal.  I also know when he tried to touch up a spot with regular paint he had a similar reaction.
1975 CB750K
Project Back in Black

Sent from my Texas Instruments TI99/4A Computer

Offline drdreas

  • Enthusiast
  • **
  • Posts: 113
  • 77' CB750k
Re: Opinions on paint job (pictures included)
« Reply #16 on: May 17, 2010, 07:16:26 AM »
here is another better photo of the discoloration I get when I wet sand the black. This is a much larger area on the cafe seat.



As an update, I picked up 3 cans of duplicolor black and will be redoing the black with this paint. Now that the rustoleum is cured, I'm going to mask off the white center stripe, rough up the black, respray with duplicolor and then redo the pinstrips in white.


Offline wildcatmahone

  • Poseur
  • Hot Shot
  • ***
  • Posts: 320
Re: Opinions on paint job (pictures included)
« Reply #17 on: May 17, 2010, 04:08:59 PM »
That "discoloration" you mention is what happens when you wetsand gloss paint and is absolutely normal and expected. That's why you cut and polish the paint to bring gloss back up once you get the surface nice and smooth. Elementary body painting. Just so you know. Make sure to do a test piece before you shoot that clear over that duplicolor.

Offline Retro Rocket

  • Eggs are hard due too a
  • Really Old Timer ...
  • *******
  • Posts: 19,279
  • ROCK & ROLL
Re: Opinions on paint job (pictures included)
« Reply #18 on: May 17, 2010, 04:19:09 PM »
That "discoloration" you mention is what happens when you wetsand gloss paint and is absolutely normal and expected. That's why you cut and polish the paint to bring gloss back up once you get the surface nice and smooth. Elementary body painting. Just so you know. Make sure to do a test piece before you shoot that clear over that duplicolor.

Saved me saying it, ALL paint will do that when wet sanded, if you want to know what it will look like cleared,  just wet a section that has been sanded and it will bring the color straight back out.

Mick
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline drdreas

  • Enthusiast
  • **
  • Posts: 113
  • 77' CB750k
Re: Opinions on paint job (pictures included)
« Reply #19 on: May 18, 2010, 02:11:26 PM »
So the gray spots that appear when wet sanded that I show in the pics in the first post are normal? If it will go away with clear, then I won't redo the black, I'll just wet sand the whole thing and then clear.

Any other people confirm that the pics look like normal wet sanding of black paint?

Thanks

Offline Stev-o

  • Ain't no
  • Really Old Timer ...
  • *******
  • Posts: 34,324
  • Central Texas
Re: Opinions on paint job (pictures included)
« Reply #20 on: May 18, 2010, 04:39:30 PM »




In the top right of this photo, it looks to me like there is a bit of a reaction in the paint.  It's hard to tell with the rest of the picture, but that corner has some good light on it and if the rest of the seat looks like that, I would say strip it and respray.  Wet sanding will give it a dull look and make black look gray, but it doesn't look to me like that part of the seat has been sanded yet. 

Seat??!?
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline drdreas

  • Enthusiast
  • **
  • Posts: 113
  • 77' CB750k
Re: Opinions on paint job (pictures included)
« Reply #21 on: May 18, 2010, 06:39:21 PM »
Its a fiberglass cafe seat. Yea you are right, the shiny part hasn't been sanded yet. Only the flat part that looks gray has. Are you saying that the gray look on the parts of the tank and seat that were sanded is normal?

The shiny parts will look that way too once I sand them.


Offline wildcatmahone

  • Poseur
  • Hot Shot
  • ***
  • Posts: 320
Re: Opinions on paint job (pictures included)
« Reply #22 on: May 18, 2010, 07:12:29 PM »
That "discoloration" you mention is what happens when you wetsand gloss paint and is absolutely normal and expected. That's why you cut and polish the paint to bring gloss back up once you get the surface nice and smooth. Elementary body painting. Just so you know. Make sure to do a test piece before you shoot that clear over that duplicolor.

I repeat, this is normal anything glossy that is sanded will become dull as you scratch the surface up. It's to do with the reflection of the light off the surface. When you sanded the paint becomes grey (dull) and you will notice specks of gloss left on the surface, these are the low spots. Keep sanding and once the surface is a uniform grey you can be certain that the paint surface is completely smooth. Thats the goal. Then you can start polishing the paint or laying the clear. Dont make me come up to Boston and do it for you.

Offline RAFster122s

  • I feel like a really really
  • Really Old Timer ...
  • *******
  • Posts: 12,367
  • SOHC4 member # 2605
Re: Opinions on paint job (pictures included)
« Reply #23 on: May 19, 2010, 04:26:39 PM »
Are you wet sanding the paint or dry sanding with the 600?
You will want to go 600, 800, 1000, 1500 before top coating as this will give you a nice smooth flat finish.
Any texture you can see in the paint will be magnified when the gloss is applied and light catches it.  So if it isn't as smooth as a babies bottom before clear it will show.
It is tough to see some things until you get the clear on, good strong lights will help you see the imperfections or blemishes you need to work out.

You are going to need to strip the Rustoleum to be safe...Apply a coat of duplicolor if you want to roll the dice but you really need to sand it back so it is flat with no texture.  Otherwise you are going to have to apply a ton of Duplicolor to build up the film thickness to the point you can flatten the paint so you don't have the texture from the dry coats.

David
« Last Edit: May 24, 2010, 01:13:17 AM by RAFster122S »
David- back in the desert SW!

Offline drdreas

  • Enthusiast
  • **
  • Posts: 113
  • 77' CB750k
Re: Opinions on paint job (pictures included)
« Reply #24 on: May 20, 2010, 08:41:27 AM »
RAF, I'm wet sanding with 600. I also got some 1000 so I will wet sand with that as well.