Wet Sanding Question

[theclock12]

Hi everyone!

Been reading a lot of the posts and threads about wet sanding. Don't worry I have no immediate plans to do it on any car probably just some random test panel.

Anyways, my question is as far as I can tell you start with a lower grit (1500,2000) and finish with a higher (2500,3000) but how long do you sand with each one and how can you tell when to move on to the higher grit? Thanks just curious! Side note can you buff out with DA using an aggressive compound?

Thanks- Jackson

[Flash Gordon]

Originally Posted by theclock12

but how long do you sand with each one and how can you tell when to move on to the higher grit?

can you buff out with DA using an aggressive compound?

Thanks- Jackson

I'm assuming you're sanding by hand? If so then you quit sanding when you see the defect removed or your butthole puckers up. At that point you go to a higher grade paper. You'll want to use the crosshatch method when doing all this (up/down then back/forth)


Yes. If you finish with at least 3000 grit you should'nt have a problem

[theclock12]

Thanks for the response very helpful and yes sanding by hand, is using the porter cable xp more effective for sanding then hand? and "butthole puckers up" wtf?

[Flash Gordon]

Originally Posted by theclock12

Thanks for the response very helpful and yes sanding by hand, is using the porter cable xp more effective for sanding then hand? and "butthole puckers up" wtf?

Sanding by hand will definitely remove more clear then working with a DA using the same grit paper/disk. For me personaly I like to sand by hand. The machine feels weird to me

As far as the butthole puckering up, just forget about that part. The part that should concern you is if and when you strike through a clear, you might poo your pants

[B&B Tennessee]

Pooing your pants through wet sanding is VERY uncomfortable - but it happens

[master detailer]

you will feel the drag on the sand paper lighten up as you work /drag I use soap w water spray to make it slide better light hand is best and better to work it longger then try to do it to fast.You can sand more but cant go back.

[theclock12]

Hmm I would've thought wet sanding by DA removed more , but hand does? If I wanted the basics backings to the DA and grits what should I get/ how many

[Flash Gordon]

Originally Posted by theclock12

Hmm I would've thought wet sanding by DA removed more , but hand does? If I wanted the basics backings to the DA and grits what should I get/ how many

Example: 2000 grit paper is more course then 2000 grit disks. Feel them for yourself and see

If you plan on just sanding scratches I would go with a 3" BP, If you plan on doing entire panels go with a 6" BP

For heavy scratches you'll want to start out using 1000 grit disks, then move up the ladder (1500, 2000,3000...)

Be sure and order at least one interface pad for each size

PS I never do this, but you should always take paint readings as you go...... Do as I say, not as I do

[tuscarora dave]

Meguiars Unigrit 3 Inch Professional Backing Plate and Adaptor Kit, backing plate with adapters, meguiars backup pad
Meguiars Unigrit 3 Inch Foam Interface Pad, foam backup pad, sanding disc interface
Meguiars Unigrit 3000 3 Inch Finishing Discs, 15 per box

and perhaps one of these machines to go along with the sanding supplies.

Griot's Garage Professional Random Orbital 3 Inch Polisher, Random Orbit Buffer, Dual Action Polisher, 3" buffer

Wet sanding with a heavier 6 inch DA can be a bit awkward as the machine itself can be too heavy to apply a real light amount of pressure to the work area that you are sanding on. The 3" electric DA's can be a nice tool to use for wet sanding. Of course there is the 6" version of everything that I linked above.

If you have a decent sized (60 gallon or larger) air compressor, there are some decent air DA polishers/sanders on the market that make sanding much easier. There are also some really nice electric (brushless DC) sanders on the market that start around $500 that are the best tools for machine wet sanding. 3M, Mirka, and Rupes are a few brands that come to mind.

Of course I realize that some of this info is for someone that would want to do advanced level sanding rather than someone just sticking their toe in the pool so to speak, but it's worth taking a look at anyway.

In the end, I'd recommend starting with the least aggressive papers (3000 grit or finer) to get a good feel for machine sanding. You can very quickly cut through today's thin clear coats so go slow and know that you just can't be too careful when wet sanding on OEM automotive paints.

Having a hood from a salvage yard to practice on (as you've mentioned) is the smartest route.

[smack]

The safest way to tell when to stop sanding is when you get all the orange peel out. When it becomes totally flat in that area stop with the aggressive paper then finish with the higher grit. If there is still a small scratch its better to learn to live with a minor cosmetic blemish than to pay to have it re cleared.