Wetsanding Guide - Saxperience

-Dan- · 23rd September 2008, 13:58

I've noticed that there isn't much on here in the way of Wetsanding guides so I though I'd post a small guide of what I did when I wetsanded a small area of my car.

A scratch is actually a couple things. If you picture a scratch or an etched mark, the edges usually consist of sharp edges that make them very visible. Looking horrizontally down the middle of a scratch, it would look either like a "V" or "U". By using something aggressive, you smooth out the edges, blending it in, making them more difficult to see. You actually remove some of the paint, making a more flush surface with the scratch.

Wet sanding is the most aggressive way of removing the paint for repair. If not done correctly, you WILL damage the paint to the point you need to have the area re-painted. Using a gritty polish or compound is much less invasive and more easily fixed.

If you choose to proceed with wetsanding, It is completely your choice and I hold no responsibility at all If you damage your car. You have been warned, and you proceed with this completely voluntarily!

Sand paper - 2,000 grit.
Spray bottle with water (helps to lubricate area)
Harsh, Gritty paint Restorer (I used Red T-Cut but others may possibly work)
Polish (Autoglym Super Resin Polish is best to use here)
Buffer (optional, but helps)
Polish Applicator pad
Microfibre towel

First Make Sure Car is completely clean to prevent further scratching and contaminants etc.

1. Spray down the area you are going to wet sand with water (preferably fill a hair spray bottle or similar and take it out with you).

2. Tear off a small 10cm x 10cm square of 2000 grit sand paper and fold it in half twice, creating a rough 5 x 5 area.

3. Spray water regularly and NEVER let area dry out. Gently rub over the scratch and the surrounding 2-3mm. Don't press too hard as it will creat uneven surface. This bit is best done with a sanding block, although I didn't when I wetsanded.

The sanding will make the area look white and will look like there is no paint there. It's normal, don't panic. Just don't sand alot, do it as little as possible. Most need less than 20-30 seconds of total sanding.

4. Apply and start rubbing area with t-cut/paint restorer by hand (applicator pad) or with rotary/machine polisher (recommended if you can get one) until paint color starts coming back. Allow to dry to a light haze, then buff off with a microfibre towel.

5. If necessary Repeat step 4 again and really buff it out until all traces of white, and the scratches from the sandpaper have disappeared.

6. At this stage the paint should still be dull, don't worry as this is just the effect that T-Cut has.

7. Polish it with AG SRP, to bring back the shine and life of the paint, and to give it a finished look. This stage works a lot better and faster If a machine polisher is used (as recommended by hopcraft).

8. If your happy with the final results, then that's it done, just finish the work with a light application of wax, to help seal it. If not then repeat the process again, however each time you do it, you take another small layer of topcoat off, so be warned that If you repeat the process too many times then It could have lasting damaging effects/need respraying.

Hope this helps people!

rowza · 23rd September 2008, 14:51

sounds good mate. got pics? wouldnt try it like lol

fossie · 23rd September 2008, 15:36

Sounds about right that fella, rep'd for it as well

Hopcraft · 23rd September 2008, 17:24

Good guide tbh mate, iirc i usually start with a 2000 grit and sanding block then finish with a 4000 grit. This makes the polishing process easier.

Then with rotory use FCP then 3M Yellow top then finish with 3M's blue top.

Back to new.

Note, this is used on new paint, never done it on old paintwork.

flee123 · 23rd September 2008, 19:57

Good guide, would do what Hopcraft said above with the 4000 too, makes paint come up better when you polish it.

Ste · 23rd September 2008, 23:14

Just as an addition, without a rotary getting a decent finish will take a very very long time. I had a go without one on my old astra and i never got it to look right. Once a rotary had a few passes it came up perfect.

-Dan- · 24th September 2008, 17:59

Quote:

Originally Posted by Hopcraft

Good guide tbh mate, iirc i usually start with a 2000 grit and sanding block then finish with a 4000 grit. This makes the polishing process easier.

Then with rotory use FCP then 3M Yellow top then finish with 3M's blue top.

Back to new.

Note, this is used on new paint, never done it on old paintwork.

Good advice

-Dan- · 30th November 2008, 15:23

Little Update:

I now have a Kestrel DA Machine Polisher, and without doubt it is a far easier and better option to try and use one, If your ever wetsanding.

Here's some links to the finer grit sandpaper recommended by Hopcraft above:

http://www.cleanyourcar.co.uk/polish...es/cat_15.html

Ideally you would want 2000, 2500 and 3000 grit paper.

If you do manage to get hold of a rotary or a DA Polisher, I'd recommend using the Menzerna Power Gloss on a Meguiars Cutting Pad:

http://www.cleanyourcar.co.uk/polish.../prod_203.html

Then if you still have hazing, gradually step down through the polishes and the pads until you reach a nice glossy finish.

Prickle^p · 30th November 2008, 16:15

good guide, but i wouldnt attempt it

shaunyboy · 21st December 2008, 00:15

Instead of T-cut i would use 3m extra fine cutting compound and buff it

http://www.elitecarcare.co.uk/3m-per...1e8843abe58832

Good guide tho mate, Nice to see some people posting guides.

Predator_R32^p · 21st December 2008, 01:04

i did wetsanding in a few places on my car, worked really well

really did feel like arghhhhh what have i done but get the polisher on it a few pass's and its find, your only fine sanding the laquer off, basiclly loads of swirl marks really, nothing to be scared of tbh

wigansaxo · 21st December 2008, 03:11

could you just use like a 4000 grit? as i wouldnt wanna try a 2000 grit for my first attempt, and after an area has been wet sanded and polished up etc etc, will it need polishing and buffing up again in the futher?

fastroadkid69 · 21st December 2008, 20:26

nice guide that, gonna have apop at that on me front bumper, cheers uddy.

Dan · 3rd January 2009, 18:26

Quote:

Originally Posted by Predator_VTR

i did wetsanding in a few places on my car, worked really well

really did feel like arghhhhh what have i done but get the polisher on it a few pass's and its find, your only fine sanding the laquer off, basiclly loads of swirl marks really, nothing to be scared of tbh

Did you polish it with a pc/udm or rotary pred? An what polish did you use?

bullit · 3rd January 2009, 20:14

he would have used his pc. try the least aggresive polish before going higher cut

Dan · 4th January 2009, 14:13

Cheers mate, just asking as I always thought you couldnt do it without a rotary?

fastsaxo7 · 31st January 2009, 10:34

hi been to my local D.I.Y shop and got some 400 wet and dry is this the wrong stuff is it 4000 i need and if so were can i get it from? thanks

-Dan- · 31st January 2009, 10:44

400 is far too harsh, and will create extremely noticable scratches, so DO NOT use it on the paintwork.

You can get 3000 from here, this is what I used, although 4000 would be even better, I can't find any links to any atm.

http://www.cleanyourcar.co.uk/polish...es/cat_15.html. You'd be best getting one of each grade, and starting with lowest (EG 2000) then working up to higher grade (3000).

Hope this helps mate, good luck.

fastsaxo7 · 31st January 2009, 10:57

ok thanks alot

Smylie · 31st January 2009, 14:08

I have a 5-6cm scratch on the rear, its nearly 1 mm deep, will this method work for it? i dont wanna try it and it to look worse lol.