roderage

i'm looking for the dummy that said to wet sand clearcoat in soapy water to get a mirror-like finish. my touchup looks worse than before i sanded it. if i find you, and you know who you are, i'm gonna wet sand your whole bike. THANKS! luckily it was only a small spot on my top tube. now i guess i'll just wait [U]another[U] week for the paint to dry....

-do not, i repeat, DO NOT SAND YOUR CLEARCOAT!!!

GeoLes

Oops!

:: sleeking away ::

d3fold

You can wet sand a clear coat, but you need to buff it after that. Wet sanding takes awhile to get the hang of, it takes a lot of practice.

bravozulu

I have done quite a bit of custom airbrush and paint. That is how to get a smooth deep finish.

I usually start with 1000 using gentle pressure then switch to 1500 and then on to 2000, use lots of water. For difficult corner areas, I will use very fine steel or brass wool. After that, you must polish. Take it slow and easy with an electric buffer, fluffy pad and polishing compound.

If you do not want to polish, you can just put a final clear coat that should flash out nice and even over your new smooth sanded prep.

I like the HOK flo klear but you can get good results wit whatever you are using.

https://www.houseofkolor.com.au/produ...ts&cat_index=6

gmason

Take advice here and don't try it on a useless piece first?

Road_Biker

I would expect a full refund for that advice! Oh, wait, it didn't cost anything. Maybe there is a lesson here? Probably not.

If you are that much of a perfectionist, how about getting a book on how cars are painted and touched up since the base-coat clear-coat system is an auto paint? Then go practice on someone's car that needs touch up paint. Practice makes a big difference in the quality of the paint repair. Painting is an art.

Personally, I would not sand and buff the clear coat. It wouldn't look perfect, but after a month of use the clear coat wouldn't be noticeable. I recently went through scratch repair on arrival of my BD Windsor Tourist. Touch up clear coat covered the scratch and it's not noticeable. I could find the spot, but no one else could. It wasn't on the top tube though.

stringbreaker

One word POWDERCOAT

x_freeride_x

You can wet sand clear coat after painting. It's a necessity for automotive applications. It works out and smooths all the imperfections in the paint surface, makes it like glass. I probably would do it on my bike because I'm so particular but wouldnt really recommend the extra work to someone else for a bicycle. Anyhow, just as bravozulu recommended, I would start lower, probably 1000, then maybe 1500. But 2000 is almost not necessary. Once you finish sanding you will have a milky white finish to your paint if you've done it correctly. Thats when you break out the polishing compounds. These actualy are a mild abrasive. They make them in different levels. Fine polish would suffice unless you wanted to work through two or three compounds. Run an electric buffer wheel over that milky finish with some polish and like magic you have a deep glossy clear shine. Hope this helps.

shakeNbake

Hahahahahahahahahahahahahahahahahahahahahahahahaha

nerobro

A proper paint job requires sanding between coats, and the final coat. It's a pain inthe butt, yes. And it makes the paint look bad when you do those 1000,1500 and 2000 grit passes. you need to be VERY, VERY sure to keep the grits seperate. And you CAN NOT go back grits.

Once you have the surface flat, and got the orange peel gone... you can then polish it. :-) and finally wax.

Painting is very labor intensive. It ends up pretty. I spent ungodly amounts of time on my GS550's body parts. they came out beautiful.

RK1963

So, do you wet sand your final clear coat?

old_alfie

A logical followup question would be who's the dummy that took the advice from a dummy and acted on it?

urbanknight

+ 1,000,000 Now I'm starting to worry that someone might take that guy seriously who suggested cutting one's self, putting the blood in a blender to spin, then drinking it before a race as a doping method.

hyunelan2

All you need is some polishing compound and you're all set. The sandpaper won't leave a nice clear finish right off, you need to polish it. You can get a small bottle of 3M polishing compound from any autoparts store, or even walmart. If it's only a small area, it's doable by hand - but much easier if you have a rotary polisher.

San Rensho 

Wet sanding clear is perfectly good advice, but as others have said, you have to know what you are doing.

After 2k wet sanding, the finish will be very dull, even if you wax it. Now you need to use rubbing compound on it, followed by polishing compound followed by wax. I would do it by hand. Be careful with a rotary polisher, you can go right through the paint in the blink of an eye if you dont know how to use one properly.

Advice is not wrong at all, you just need to finish the job. Progressive abrasives are your friends.

Dr.Deltron

All these posts with differing opinions...

But I must start by taking issue with the above quoted statement...

A proper paint job does NOT REQUIRE sanding between coats!
Unless you have passed the end of the window for the paint to be "open".

Nutshell lesson...for a steel frame.

Jasco off all the old paint.
Sandblast with a small pressurized blaster using #60 mesh sand to clean off the remaning little tidbits & give the primer some "tooth" to grab.
IMMEDIATELY spray a primer/sealer. I use PPGs DPLF in appropriate color.
If there are rust pits & other surface blems, I use DX271 primer. It's like spray bondo.

NOW I sand the whole thing and make the surface perfect.

Then clean with DX330 Wax & Grease Remover.

Then comes a reduced coat of DPLF for a complete sealer base.
This coat should end up very smooth, so little or no sanding needed. If I do have to sand any spots, I use 800 and go lightly so I don't sand through the sealer.
Now I have about 3 days to get the color on. If I wait more than that, It's THEN recommended to scuff & respray the sealer. Now I have about 3 MORE days to get the color on.

I use Sikkens colors from my mixing system, as they cover in 3 coats or less. Drys in minutes. So fast that I can tape over it by the time I have cleaned my spray gun.
Now I have about 24 hours to get the decals & clear on.
If longer, THEN I have to sand & respray the color.
Best to avoid that. Cost = Time & Materials.

NOTE: DO NOT SAND mettalic or pearl colors unless you are planning to respray the color.
Sanding will ruin the little metal or pearl flakes & you have to respray.
This is why metallic & pearl powdercoat colors need a clear coat. Cable housings can rub the flakes just like sanding would. So if you get a metallic or pearl PC, you can...
Have a clear PC done on top of the color. If you are applying decals, they have to be specially made to be PCed over with PC.
If you have standard decals...
Clean the PC with DX330, DO NOT SAND OR SCUFF, apply decals, spray 2042 clear.

Back to PAINT...

Now I've got color on and can spray the clear. I use PPG's 2042 clear and spray a medium light coat first to get a tacky base. Wait 20 minutes. Spray a wet coat. Wait 1/2 hour. Spray another wet coat, but this time spray quickly and try to get the paint on fast enough that it's all "wet" at the same time.
Using a slower reducer helps considerably.

This point is KEY!

Having all the paint wet at the same time will make it so it all flows out nice & smooth & GLOSSY!
In other words, it's best to SPRAY the final gloss, than to get it by polishing!!!!

Polishing a CAR is easy with power tools. Bike frames are a whole other universe!

As for roderage's touch-up, sounds like you'll HAVE to polish.
ORRrrrr...if you have some auto quality clear (such as the 2042) & an airbrush (single action is easier than a double action) you can do a pro touch-up.
Spray a dab of clear right on the touch-up spot. Let dry for 20 min. Spray a second shot at the touch-up that's just a tad larger than the first spot. Wait 20 min. Spray a 3rd shot, again, just slightly larger than the last.
Immediately replace the clear in the gun with JUST reducer. Adjust the paint volume DOWN on the airbrush and spray the reducer around the edges of the touch-up spot. Wait 10 minutes & repeat.
What this does is thins out the edges of the touch-up so it flattens out and blends the fuzzy edges into the existing paint.
Initially, this may make the touch-up appear milky. Let dry overnight and some 3M Finesse polish will eliminate the milky appearance.

Now, if the touch-up is kind of lumpy...
Spray 2 shots of 2042 just on the touch up. Wait overnight. Mask around the touch-up area, so you have a sanded area that's not much bigger than the touch-up itself. Sand it smooth with 800.
Proceed from the ORRrrr line above.

NOTE: These steps will work best with compatable materials. If you did the touch-up with say Testors or One-Shot, then this will NOT work! The 2042 will ruin the touch-up.
Do a test on a piece of white plastic PVC pipe FIRST if you're not sure.
As a note, 2042 DOES go over artists acrylic paints! The kind in the tubes at the art supply store. The ones that are like oil paints, only water based. Might be easier to match than Testors too.

Hope that's helpful.

Good luck to all you up-&-coming bike painters!

Next lesson...using cuy vinyl masking for graphics. Stay tuned.

GlassWolf

wet sanding works, when you know what you're doing.
you need to buff and polish it out after wet sanding. it's supposed to be hazy after it's sanded.

Dr.Deltron

This is true. For a CAR, where you can easily use power tools. Not so much for a bicycle.

Proper spraying technique is your best friend when it comes to making a glossy bicycle frame.
IF you know what you're doing.

DaveSANYYZ

I don't think the OP did a repaint. He only mentioned it as a touch-up job. Skip the power tool since the OP doesn't seem to know/have experience with this; especially if the spot is near an edge/another tube. Get some polishing compounds (skip the turtlewax rubbing compound stuff), or something like Meguairs' ScratchX and get it back to a shiny state by hand.

GlassWolf

people were doing all of this by hand long before we had power tools.