wet sanding and reclearing.

I would wet sand with 1500 grit spray about 4-5 coats of clear. Then wet sand with 1000, 1500, and 2000 then polish it out and wax. Read the can and see what cure time is before polishing
 
Lasthope05 said:
If you are re-clearing the hood you should not be polishing it before hand or sanding with fine paper. I did a lot of prepping for repaints for resprays and learn how to paint also.

1) Wet sand with 800 grit (600grit for primer)
2) Prep sol wipe down(Very important. Several times to prevent fish eyes.)
3) Apply clearcoat
4) Cut and Polish (Look at the technical sheets of the clear. It will tell you how many hours before you can do this.)

You should not wet-sand(light grits) and polish before you re-clear it. The paint needs a ruff surface for it to adhere to. Also don't worry about the 800 grit wet sand scratches. The clear coat is going to fill them in when you do your "wet coat."
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I agree with this 100%! :props:
 
Last September I sprayed a motorcycle blue pearl metallic and white pearl for a friend. The front fender got a few bugs in it after 2 coats of clear so I sanded it lightly with some 600 grit, wiped it with wax and grease remover and shot two more coats of clear on it and it turned out phenominal. A few months ago I was spraying another motorcycle yellow and two giant bugs kamikazeed the clear after one coat. I picked them out, smoothed it up with 600 grit and shot three more coats of clear, no scratch marks. Granted this was with 2 part automotive clear so your results may vary with rattle can.
 
Tiffanator said:
Last September I sprayed a motorcycle blue pearl metallic and white pearl for a friend. The front fender got a few bugs in it after 2 coats of clear so I sanded it lightly with some 600 grit, wiped it with wax and grease remover and shot two more coats of clear on it and it turned out phenomenal. A few months ago I was spraying another motorcycle yellow and two giant bugs kamikazeed the clear after one coat. I picked them out, smoothed it up with 600 grit and shot three more coats of clear, no scratch marks. Granted this was with 2 part automotive clear so your results may vary with rattle can.
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I've seen a rattle-can of clear that was it self two parts, at Wesco. You break a seal inside the can and it mixes in the catalyst, you just have to use it right away because it will harden in the can. After great success with regular rattle can clear, I gotta try the good stuff next. :dblthumb2:
 
Lasthope05 said:
No, 800 grit is actually on the light side for prepping. You are wetsand to to get a smoother and more uniform finish. There is a difference in wetsand for painting and wetsanding for paint correction. Wet sanding in painting uses 600-800 grit to roughen and prep the surface. Wet sanding in paint correction uses 1000-4000.

Using too fine of a grit will not allow the new respray to properly bond. You also dont have to worry too much about sanding through as carbon fiber hoods are gel coated are pretty hard and much thicker than standard clear. Just be smart about it and dont sand the same spot over and over again. All you want to do is rough up the surface. Unlike in detailing your are not trying to remove defects so you're not continuously sanding one spot.

What is the current condition of the hood? IF the gel coat is not compromised/oxidized you could use a scuff pad in lieu of sand paper if you are scared of sanding through to the weave.

3M™ Paint and Body Scuff Pad, 03193, 6 in x 9 in, 20 per case
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the hood is in phenomenal shape. no oxidation, no yellowing of the gelcoat. reason i want to re-clear is i have 2 fine cracks in the gel/clear. how they got there, i don't know. but with the temperature changes(living in colorado)they grew quite fast. read up alot on these issues and they way to stop it from getting bigger is to reseal hence the reason i am going to re-clear. i would take it to a body shop but i already have a new one and it's on the car. i want to repair this one myself. i have always been a do it yourselfer and know i could tackle this.

so, do you think a scuff pad would work well? if so, what or which grit should i use? now i am breaking into a whole different world. never really used scuff pads too much.

again, thanks everyone for all your replies.
 
corolla619 said:
the hood is in phenomenal shape. no oxidation, no yellowing of the gelcoat. reason i want to re-clear is i have 2 fine cracks in the gel/clear. how they got there, i don't know. but with the temperature changes(living in colorado)they grew quite fast. read up alot on these issues and they way to stop it from getting bigger is to reseal hence the reason i am going to re-clear. i would take it to a body shop but i already have a new one and it's on the car. i want to repair this one myself. i have always been a do it yourselfer and know i could tackle this.

so, do you think a scuff pad would work well? if so, what or which grit should i use? now i am breaking into a whole different world. never really used scuff pads too much.

again, thanks everyone for all your replies.
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Scuff pads work expectationally well for preparing a panel for respray. They are pretty much scotch brite pads and come color coded for aggressiveness/coarseness in automotive use. Grey = fine and Red = medium. This can easily be purchased at your local auto parts store. What you want to be using is the grey pad, with or without scuff paste.

Scuff paste is basically an abrasive paste use in conjunction with a scuff pad to give you faster and more uniform cut. It's not totally necessary but it makes things a bit easier.
 
Lasthope05 said:
If you are re-clearing the hood you should not be polishing it before hand or sanding with fine paper. I did a lot of prepping for repaints for resprays and learn how to paint also.

1) Wet sand with 800 grit (600grit for primer)
2) Prep sol wipe down(Very important. Several times to prevent fish eyes.)
3) Apply clearcoat
4) Cut and Polish (Look at the technical sheets of the clear. It will tell you how many hours before you can do this.)

You should not wet-sand(light grits) and polish before you re-clear it. The paint needs a ruff surface for it to adhere to. Also don't worry about the 800 grit wet sand scratches. The clear coat is going to fill them in when you do your "wet coat."
Click to expand...

When painting adhesion is first and foremost. For this to happen the existing surface must be clean and then sanded with the proper grit paper. Sanding is done so that the new cost will have something to "grab" on to or creates a mechanical bond between it and the existing surface.

Sanding grits of 2000, 2500, and 3000 are intended for compounding and polishing. These work well with the particle sizes designed in todays product that will remove scratches in this range. Take a look at Menzerna chart below and the corresponding grit table to the right.

MenzernaProducts.jpg


Preparing the surface for painting should be done as described above. Wet sanding with 800 to 1000 grit max is spot on for proper adhesion of the new clear. Prep-sol is a paint cleaner made by Dupont and it specially formulated to remove silicone, oils, and contaminates making the surface ready for painting. If this step is not done properly the paint in it's liquid state will begin to separate in spots leaving little craters called "fish eyes". There are additives for paint called fish-eye removers so you might want to do a little homework before diving right in. Talk to the guy behind the counter at the paint shop and tell him what you want to do and he'll provide you with some direction..

Remember; your surface preparation will dictate the quality of the finish once complete..
 
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