View Full Version : bits in clear coat?
slywhite666
01-22-2009, 09:16 AM
hi all, i have just put my first coat of 2k clear coat on a wing and it has bits in it, how do i go about getting these bits out. they are small bits of dust amd what looks like tack cloth, can i sand them with 1500 wet and dry and recoat it all or do i have to sand it all.
also how long should i leave it between re-coating clear?
you should try to get them out when the clear is still wet IF you can do so without touching the wet clear. If not you will have to sand it out. Depending on how deep (which layer of clear it is under or on top of) will determine if you will get it all out or not. Alot of dust is colorless and sands out easily. If it has a color to it that you can see, it will have to be removed completely
slywhite666
01-22-2009, 09:26 AM
sorry i dont mean to get it out while still wet, and its in the first coat of clear and the bits are colourless.
Serge
01-22-2009, 09:43 AM
Its normal to have some dust in a garage sprayed part. Most of them become invisible when polished however. If you have som 1500, then use it wet to nib the dust particles then polish the part to a shine...it might be all you have to do.
If the dust is visible like big visible lint or something like that then you will have to sand it out and probably re-clear.
You can sand, I would sand 800 wet, and re-clear any time after the clear coat has hardened. If you dont give it enough time the clear will wrinkle when you spray fresh clear on it. So wait at least 3 days before recoating and a week if you can. Naturally, the parts should be in a warm place (at least 70) for them to cure properly. Clear does not cure as fast in a cold garage.
What 88 was saying is that when you are painting, if you see a visible piece of lint in your clear, you can take some tweezers and pick it up while the clear is still wet. You then just give it a little spray to even it out. This will create a small dimple in the clear coat that will sand and polish easily. Its better than having a visible dust particle in the clear coat that requires a re-do...
A low speed polisher is a must when spraying in a garage and polishing is part of painting cars, that's how we generaly deal with small imperfections. Maybe that's the step you were missing.
slywhite666
01-22-2009, 10:01 AM
thanks for that serge, much appreciated. my garage is at 20 degrees celcius, i ahve some pics fir you to see what i mean. i have had it in the past where i have re-coated clear to soon and that cost me very dearly and have learnt from that. i need to invest in a power polisher. how many coats of clear would you recommend i put on to be safe for sanding and polishing.
do i need to leave it a week or so between coats of clear if no sanding is needed or would half an hour be ok before re-coating.
http://i152.photobucket.com/albums/s170/slysgti6/HPIM1779.jpg
http://i152.photobucket.com/albums/s170/slysgti6/HPIM1778.jpg
http://i152.photobucket.com/albums/s170/slysgti6/HPIM1777.jpg
Serge
01-22-2009, 10:10 AM
Between coats, when spraying clear you should wait for the previous coat of clear to become tacky, not stringy before spraying the next coat.
If you are color sanding, that is sanding it flat to remove all orange peel then you should put at least 3 coats of clear on the part since you will be sanding close to 1 so 2 are left on the part.
However, if you are just nibbing dust then 2 coats is fine since you are not going to sand the orange peel off but just the tip of the dust particles you will not be taking any thickness off the coating...
The power polisher is a must. From what I see in the pictures (although its difficult to tell for sure) you could nib the dust with 1500 wet then polish and be done. I dont see anything there that warants a re-coat...
Len has a good deal on Makita polishers in the store and with Surefinish you only have to buy one polish wich is quite economical...a few pads and you are set...
slywhite666
01-22-2009, 10:17 AM
i like the idea of the polisher off len but postage would cost me a small fortune to the uk, so just to clarify i need to let this first coat fully harden, then sand with 1500 grit wet and polish but if i go to deep i need to leave a week or so then re-coat, sorry for all the questions but dont want to mess this up as its not my car its going on, thanks.
Clarkey
01-22-2009, 01:41 PM
Personally I wouldn't bother doing anything about that, all the parts I've painted have ended with quite a lot of dust in, once color sanded and buffed you can't see any evidence of it, you definitely need a machine polisher though.
Also the clear will cure slow in the woeful temperature over here, I wouldn't want to recoat for at least a month unless it's been force cured.
slywhite666
01-22-2009, 02:11 PM
thanks for that clarkey, i have a brick garage that gets up to a temp of 30 degrees celcius and i keep it like that for about 3 hours and then drop off to about 20 degrees for a few more hours, i do test patches on the wall over previous paint tests and did today after the first coat of clear re-coated after half hour and it didnt crack or anything and then did it again after another half hour and all was fine again.
what sort of clear are you using?
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