Is wet sanding required before buffing?

Discuss anything after that final masking comes off.



Settled In
Posts: 81
Joined: Sun Aug 14, 2011 11:10 am
PostPosted: Sun May 29, 2022 8:35 pm
Hi guys,

Always wondered this question.

I painted parts of a white car last week, and it is barely even noticable without buffing. I still want to do it anyway.

I use a medium pad with M105 cutting compound, does this have similar effects to wet sanding with let's say a 1500/2000 grit? If so, why even bother wet sanding?

Could get away with just using M105/205 combo and not wet sanding at all?

User avatar

Top Contributor
Posts: 2762
Joined: Sun Dec 16, 2012 4:46 am
Location: Canberra
Country:
Australia
PostPosted: Sun May 29, 2022 10:51 pm
Wet sanding is for taking out the peel in the surface, removing the texture so the surface is perfectly flat. In repair work this usually isn't necessary since the painter should put back the same peel as is on the rest of the car, from the factory, and then just denib to remove any dust/dirt in the surface.

If the job doesn't call for a perfectly flat finish then wet sanding, again, isn't necessary.

In repair work there are often dry areas where the paint has been blended or the painter didn't get a full wet finish. These usually respond well to just buffing.

So, the answer to your question is "No, wetsanding is not necessary prior to buffing", only when required to achieve the necessary degree of surface flatness.
Chris



Settled In
Posts: 81
Joined: Sun Aug 14, 2011 11:10 am
PostPosted: Mon May 30, 2022 7:49 pm
NFT5 wrote:Wet sanding is for taking out the peel in the surface, removing the texture so the surface is perfectly flat. In repair work this usually isn't necessary since the painter should put back the same peel as is on the rest of the car, from the factory, and then just denib to remove any dust/dirt in the surface.

If the job doesn't call for a perfectly flat finish then wet sanding, again, isn't necessary.

In repair work there are often dry areas where the paint has been blended or the painter didn't get a full wet finish. These usually respond well to just buffing.

So, the answer to your question is "No, wetsanding is not necessary prior to buffing", only when required to achieve the necessary degree of surface flatness.


Got it, thanks.

User avatar

Board Moderator
Posts: 9878
Joined: Fri Oct 20, 2006 12:40 pm
Location: ARIZONA
PostPosted: Tue May 31, 2022 9:00 am
Depends on whether you are wanting it perfect or acceptable?

I have sprayed jobs that were acceptable straight out of the gun. No buffing needed. Others have had orange peel and needed to be sanded first.

If you are wanting a Show Car paint job, then I would highly recommend learning how to wet sand and buff. You can do a Search on here for Cut and Buff or related titles.

I dumped the Meguiar's M105 a while back and started using the M100. Much better product.
1968 Coronet R/T


ACTS 16:31



Fully Engaged
Posts: 101
Joined: Mon Jan 02, 2023 5:19 pm
Location: Kansas, sunflowers & tumbleweeds
Country:
USA
PostPosted: Fri May 19, 2023 8:55 am
this thread is exactly my quandry. not after show car. I had a bad experience wet sanding my first job and nvr got the fine scratches out.

definetly don't want to wet sand and risk that again when i feel my job is acceptable as is and I really dont need a perfect flat surface.

but just going straight to buffing is what iv'e been used to seeing in the past. I may do that. but then the crud in hard places problem.

so mcquires m100 is the stuff to use if your going to buff only? then wax?

thank you, I get the experts probably scoff at not finishing out with wet sanding etc, but I drive my cars a ton and race it a few times a year. (runs quarter mile, 11.80's at 114mph)

in reading about mcquires m100 sounds like you still need to polish after using it?
can I go straight with a polishing compound? the m100 talks about removing scratches and other deep affects that I don't have. want to leave as much clear coat on as possible. honestly the whole cut/buff thing make me far more nervous than painting the car. ie; the bad experience.
Eric

User avatar

Board Moderator
Posts: 9878
Joined: Fri Oct 20, 2006 12:40 pm
Location: ARIZONA
PostPosted: Fri May 19, 2023 10:23 am
Problems with wet sanding can be reduced to a couple of things:
1. Not enough clear coat applied.
2. Sanding too much on edges or body lines where the clear is thinner.
3. Failure to remove the previous grit scratches. All 1000 grit scratches must be removed by the 1500 and etc. with the 2000. Try sanding in a 45 degree angle with your first grit and then reversing the angle direction on your next grit. When all the little X shaped scratches disappear you have reached your goal. Also, wiping the panel with Wax and Grease remover and a rag will offer you a quick look at your progress.

The Meguiars M-100 on a rotary buffer with a twisted wool pad will produce great results.
You can follow it up with a foam polishing pad and polishing compound. I like the Menzerna Super Finish 3800 Show Car Polish for the final go around.

With the rotary buffer, you want to make sure the pad is spinning OFF the edges and body lines and not INTO them.
1968 Coronet R/T


ACTS 16:31



Fully Engaged
Posts: 101
Joined: Mon Jan 02, 2023 5:19 pm
Location: Kansas, sunflowers & tumbleweeds
Country:
USA
PostPosted: Fri May 19, 2023 11:38 am
good info.

upon dwelling on it a bit, I just don't want to wet sand. don't want the risk and not after perfection.

now, I wouldn't mind a polishing if that would take out the minor op or even 50 percent of the op.

any folks offer method and compound for just a polish? will it achieve what i'm after you think?

It definetly appears that a wet sand/cut buff is as much an art as painting. rather not have a trial and error on this particular car as its an 8 year complete self restoration. i'm not one to cut corners when it gets down to it but I just don't want to risk fine scratches again or take off most of the wonderful clear coat doing it. and yep, I know all about burning thru edges and having to use a touch up brush on a brand new paint job. thats was my first and only job but not gonna have all that disappointment again. this is my second paint job.

thank you, I apprciate this info a ton! anyone just do a polish please chime in.
Eric

User avatar

Board Moderator
Posts: 6672
Joined: Tue Feb 24, 2004 7:00 pm
Location: central Ohio
Country:
USA
PostPosted: Sat May 20, 2023 4:34 pm
Okay, I'm just going to say this coming at it from a different point of view..... I am a pro furniture restorer and conservator. Furniture is a pain in the butt to cut and buff because we are dealing essentially with NOT metal shapes which enhance style lines. We deal with wood which may or may not give us the best lines for a cut and buff. What I have found over the years with a lot of wood, metal, and plastic materials is that a compounding, buffing, or polishing is pretty much worthless without a sanding cut. WHY? I think it's fairly simple....things are just not level. It's all about depth of image and reflection. Without leveling a surface your further attempts at "enhancing" the look of the clear end up looking more like a micro fine distortion of the image. It even influences the "color" as that is why sanding of clears is called color sanding. Every year or so for the last 43 years I've done some sampling of "skipping" the cut but still doing some more buffer work..... nope, no improvements for me..... just an opinion......
Metal, wood, fiberglass, we work it all... www.furniturephysicians.com We can restore the irreplaceable!

User avatar

Top Contributor
Posts: 2762
Joined: Sun Dec 16, 2012 4:46 am
Location: Canberra
Country:
Australia
PostPosted: Sat May 20, 2023 9:21 pm
Buckwheat wrote:now, I wouldn't mind a polishing if that would take out the minor op or even 50 percent of the op.


Just buffing will take out, or at least reduce the OP, but you'd need to use a very hard pad and do it many times. Also, even using a hard pad, you'll be wearing down the low spots as well as the highs and so the risk of burning through actually increases. It's also more difficult to judge where you're at during the process. Wet sanding is much more controllable. When using a hard block you're only taking off the highs and the lows remain visible as shiny spots so you can stop when you reach the desired point.

Buckwheat wrote:I had a bad experience wet sanding my first job and nvr got the fine scratches out.


You just didn't go far enough with the finer grades to take the scratches from the previous sanding out or started with too coarse a grade of sandpaper. Sanding in different directions, as mentioned above, will help you see the scratches that you need to get out. Often some practice helps - put a few coats of clear on a scrap panel and practice before you start doing it on your project car.

Buckwheat wrote:so mcquires m100 is the stuff to use if your going to buff only? then wax?


There are lots of really good compounds these days. The Meguires products are excellent but I find better results from the 3D ACA500. That may be just me and my buff and style. I do use a rotary initially, then a final finish with a swirl remover on a Cyclo dual head polisher.

One important thing. Don't wax or seal fresh paint. Paint continues to dry by evaporation of thinners over quite a long period. If you seal the surface that evaporated thinner can't escape and you may have problems down the track. You can polish with a polymer product but don't wax and definitely never use a paint sealant like the ceramic or acrylic products out there for at least 3 months after you've applied the new paint.
Chris



Fully Engaged
Posts: 101
Joined: Mon Jan 02, 2023 5:19 pm
Location: Kansas, sunflowers & tumbleweeds
Country:
USA
PostPosted: Sun May 21, 2023 9:31 pm
Excellent info and thank you.

I painted the doors/fenders/hood/trunk today, came out great as the first parts i'm ecstatic.

i'll have to say shame on me for wanting or thinking skip the cut/buff. that first job makes me scared to death to scratch this one up. I notice the what i call minor orange peel on the larger panels a bit more as i expected. I went 4 coats base, 4 coats clear on these figuring i may want to cut/buff.

so heres my million dollar question: I will wet sand, and what is the safest finest grit sandpaper to use from start to finish and safest compound(s) to use as well as what king of buffer is easiest to use?

I was thinking maybe a small hand type buffer? I know these questions likely asked before but i'm just asking for fresh info in regards to my wanting to use fine grit stuff with little to no chance of scratches. I appreciate the patience from you pros on my many questions. I just want to be sure, been restoring this car since 2015. Eric
Eric
Next

Return to Cut, Buff, Polish & Detail

Who is online

Users browsing this forum: No registered users and 43 guests