Wetsanding and buffing fresh paint

[Kevin Brown]

I was indeed puling sanding marks out.

I also use the DA Microfiber Discs in the exact same manner.



Guess I was feeling a bit nostalgic.



I also wanted to show Tim that by just because you may use the edge of the pad to buff, you won`t necessarily create severe string marks. I want him to learn to rotate the buffing pad to better contour to the panel shape when using the edge, as things can go awry quickly if the full weight of the machine is place upon the edge.



Using very light pressure in that shot and quite a bit of water, so the paint was only marginally warm. Always like to check the `blend` so I was walking it out past the affected area.... :

[RaskyR1]

Those little MR-30 rotary polishers look sweet! Nice and small for tight areas.



`70 Chevelle? Nice to see that most the trim was off too.

[Kevin Brown]

Yeah, that`s what I thought too until I saw the last picture.

Gotta admit, that last one could be misunderstood. Especially with the drum buffer comment. :faint:



I`m simply keeping the pad in contact with the paint as I check the area I`ve just buffed. There`s very little pressure on the pad, and it`s not being held in place for defect removal- just a constant slow movement as I check the area.



Now, if I just jam nut a long stud onto the spindle, stack a dozen or so pads side by side... maybe wool to the left and foam to the right... :bolt:



Thank you, sirs.



Just a note: I learned a long time ago not to move the buffer parallel with long edges or ridges. If the pad happens to roll up onto the drip rail, it`s not so dramatic a deal to lift, or pull it away. But, if the wheel , or more accurately, my arm motion is traveling parallel to the rail and it rides upon it, it takes a bit more time to get it under control. As a guy gets better with the rotary, no biggie. Still, no negatives to polishing 90 degrees to the rail or ridge.

[David Fermani]

Again, great info Kevin. You should write a paper on all these things!

AWouldn`t it be cool to have a disc that allowed us to individually place our abrasive particles into a hard, pin-holed backing?



Each abrasive grain would be attached to a pin head, and you could stick the pin in the pin-holed backing.



I`d get a few thousand of the pins with the built-in adjustable coil springs, so I could dial in the "interface affect" I`d need for the job. Or, for flat sanding, I`d just use the non-springed pins.

What I`d like to see is a liquid sanding abrasive that can take the place of traditional sandpaper. Or maybe a liquid that will bump up the cut of a super fine paper(or pad) that can be used for correction.

[C. Charles Hahn]

What I`d like to see is a liquid sanding abrasive that can take the place of traditional sandpaper. Or maybe a liquid that will bump up the cut of a super fine paper(or pad) that can be used for correction.

You mean something like this:



https://buyat.ppg.com/refinishProduc...5-425c44e58fbf

[David Fermani]

SX Series Cleaners and Prep were designed to penetrate the pores of the substrate, float contaminants to the surface and remain wet enough to be wiped clean. They will assist the refinish technician to thoroughly and quickly prep a surface to be painted or blended.

Interesting. Seems more like a surface prep agent than a correction type accessory?

[C. Charles Hahn]

Interesting. Seems more like a surface prep agent than a correction type accessory?

Well, yes, that`s what it is marketed for... but it also says it`s a 1000-1200 grit equivalent. I can`t help but look at that stuff and wonder if it could be put to use as a correction accessory (or depending on its properties, reformulated to work for corrective purposes).



I`ve never used a sanding paste (though I know several different ones exist, just today I was at the PBE shop getting touch-up paint mixed for a job and they had an SEM sanding paste and some DuPont sanding paste on the shelf that appeared to be similar to this PPG product) so I don`t know exactly what it does to "penetrate the pores...and..float contaminants to the surface."

[Kevin Brown]

Barry and David-



Will you have the Barry Squareysâ„¢ or the Davidiscâ„¢ Sanding System at the event?



Ready to place a $10,000 opening order... at least for the Davidiscâ„¢ stuff...

[Kevin Brown]

... What I`d like to see is a liquid sanding abrasive that can take the place of traditional sandpaper....

Unless you had a specialized pad to apply the liquid, all you`d have is a grinding paste, or a compound. In other words, if the particles were free to roll about versus remaining stationary to the pad, there would be less cut and an ability to contour to the surface. This would be no different than what we get when all the abrasive particles attach to a pad as we polish. It wouldn`t even be similar to something as pliable as an Abralon disc.



If you used a pad that was very stiff or non-pliable, the particles would be forced to roll between it and the paint. This would not be as much of a problem, but you`d still see less cut, or in fact, a lot of squiggly scratches as the abrasives rolled about. Similar to swirls, or hazing. No leveling, in the true sense of the word.



If you used a pad that was very stiff and the particles attached to it, then were back to a sanding disc, which we are trying to get away from, as you`ve stated.

...Or maybe a liquid that will bump up the cut of a super fine paper(or pad) that can be used for correction.

Bump the cut? Do you mean to make it cut deeper, or to keep it clean so that it would cut consistently?

[C. Charles Hahn]

If you used a pad that was very stiff or non-pliable, the particles would be forced to roll between it and the paint. This would not be as much of a problem, but you`d still see less cut, or in fact, a lot of squiggly scratches as the abrasives rolled about. Similar to swirls, or hazing. No leveling, in the true sense of the word.

Hmm... well that`s true if we`re talking about a tool with a "rotating" pad, but what about that sort of liquid abrasive used with a pad on a tool that does not rotate? Like, say, a palm sander such as is used for woodworking? Or an in-line sander like body shops use to shape body filler, set up with a much shorter stroke length to facilitate finish-sanding?

[Kevin Brown]

Hmm... well that`s true if we`re talking about a tool with a "rotating" pad, but what about that sort of liquid abrasive used with a pad on a tool that does not rotate? Like, say, a palm sander such as is used for woodworking? Or an in-line sander like body shops use to shape body filler, set up with a much shorter stroke length to facilitate finish-sanding?

Regardless the type of pad or method used to create movement, the particles are either going to be pushed along at the same rate of speed if they`re attached, or they`re going to roll along, for lack of a better term. They will roll in opposition to whatever is moving them. Assuming the abrasive aren`t round like a ball bearing... they`ll tumble. Perhaps tumble is a better term.



So, they`re either attached at some point, or unattached.

The stroke doesn`t really matter.



As for short stroke versus long stroke, I don`t buy into the short stroke for fine sanding and long stroke for coarse sanding theory:



Machine Stroke article



I prefer the larger stroke machine unless I am working in an area that does not permit it, or on a project that is too delicate to take the speed of motion (or potential imbalance of the machine).



Am I making sense? I hope I understood your point... :redface1:

[C. Charles Hahn]

Yeah, I think you understood what I was getting at Kevin. I was just thinking based on your "rolling" abrasives remark that if the particles were "rolled" in a different sort of manner (or, as you put it, "tumbled" differently) it might change the outcome. Obviously a "rock tumbler" works to create a polished finish on objects placed inside it by `leveling` roughness, so why couldn`t a similar outcome be had with the development of a liquid leveling cream or paste that essentially creates a "rock tumbler" between the pad and the finish being worked on?



If it won`t work, it won`t work... but I think David was onto something since if done right, a liquid sanding solution could not only displace traditional sandpaper, it could make post-sanding cleanup even easier by incorporating the "slurry" with the carriers for the abrasives.



What can I say? I like going against the grain (pun unintentional of course) :nerd1:

[Kevin Brown]

Okay.



So, forget sandpaper for a moment.



Instead, let`s make a sawing rope to better create the visual.



Take a strong piece of rope, and smear pliable glue all over it.

Next, place the rope on a sandy beach, and roll the rope so that it is covered in sand.

Let the glue dry.



Now, find something to saw in half. How about a park bench made from wood? You pull from one end of the rope, and I`ll pull from the other end. We`ll pull it taut, and walk back and forth, creating a sawing motion to cut through the wood bench. As we pull, a channel is cut into the wood, and it is shaped very similar to the circumference of the rope.



After about six days, we cut through the bench, and are eventually arrested for defacing public property. :suspicious:



Sandpaper has the same sort of effect.

The idea behind using a sheet or disc or sandpaper is to affect the item being sanded so that it takes on the shape of the paper or disc. Generally, typical sanding sheets and discs are flat and somewhat rigid, with an ability to sand something level. Other materials, such as net mesh, cloth, or foam allow the sanding grains to better contour to complex shapes, but they still use abrasive that are attached to them so that they can plane material from the sanding surface.



Now, if you use loose abrasive grains to accomplish work, you`re not really planing anything- you are, however, grinding it away. Which is exactly what compounds and polishes do. In fact, if we simply took dry handfuls of sand and rubbed them across some surface, we would accomplish the same thing, only there would be nothing to bind the sand together, nothing to keep it from blowing away, and nothing to assist its cutting potential (such as solvents, or buffering agents that are designed to keep the sand debris-free).



So, when David is thinking of a sandpaper replacement, he is essentially saying he wants an abrasive substance which is instilled into a liquid. To me, this is already available.



BTW- I just looked at your site, and it is very simple, and I really think it is charming.



I mean, easy to navigate, I can read through it in minutes, there`s no fluff or BS.

It makes a guy want to hire you, as it seems so "un-overblown".



The pics are very good, too, so it looks as if your work is top-notch.



I do think you could update the 2005 article and replace it with something more relevant to YOU, and your insight as to what detailing is. Oh yeah- as much as you seem to enjoy this thing we call detailing, you must be pretty competent at it.... so... RAISE YOUR PRICES !!!! :

[C. Charles Hahn]

Okay.



So, forget sandpaper for a moment.



Instead, let`s make a sawing rope to better create the visual.



Tape a strong piece of rope, and smear pliable glue all over it.

Next, place the rope on a sandy beach, and roll the rope so that it is covered in sand.

Let the glue dry.



Now, find something to saw in half. How about a park bench made from wood? You pull from one end of the rope, and I`ll pull from the other end. We`ll pull it taut, and walk back and forth, creating a sawing motion to cut through the wood bench. As we pull, a channel is cut into the wood, and it is shaped very similar to the circumference of the rope.



After about six days, we cut through the bench, and are eventually arrested for defacing public property. :suspicious:



Sandpaper has the same sort of effect.

The idea behind using a sheet or disc or sandpaper is to affect the item being sanded so that it takes on the shape of the paper or disc. generally, typical sanding sheets and discs are flat and somewhat rigid, with an ability to sand something level. Other materials, such as net mesh, cloth, or foam allow the sanding grains to better contour to complex shapes, but they still use abrasive that are attached to them so that they can plane material from the sanding surface.



Now, if you use loose abrasive grains to accomplish work, you`re not really planing anything- you are, however, grinding it away. Which is exactly what compounds and polishes do. In fact, if we simply took dry handfuls of sand and rubbed them across some surface, we would accomplish the same thing, only there would be nothing to bind the sand together, nothing to keep it from blowing away, and nothing to assist its cutting potential (such as solvents, or buffering agents that are designed to keep the sand debris-free).



so, when David is thinking of a sandpaper replacement, he is essentially saying he wants an abrasive substance which is instilled into a liquid. To me, this is already available.

Right. I think what we`re really getting at is being able to use a liquid "compound" to level much deeper defects in a controlled manner -- say a liquid that can be used to effectively and quickly remove orange peel instead of resorting to 1000-3000 grit papers/discs.



Then though the debate becomes whether a liquid in that context would do a consistent and reliable job or not as compared to the papers and discs. Of course this primarily would be useful in production environments where having to constantly consume expensive sanding supplies hinders profitability, and a liquid product should be much cheaper and help the bottom line.

BTW- I just looked at your site, and it is very simple, and I really think it is charming.



I mean, easy to navigate, I can read through it in minutes, there`s no fluff or BS.

It makes a guy want to hire you, as it seems so "un-overblown".



The pics are very good, too, so it looks as if your work is top-notch.



I do think you could update the 2005 article and replace it with something more relevant to YOU, and your insight as to what detailing is. Oh yeah- as much as you seem to enjoy this thing we call detailing, you must be pretty competent at it.... so... RAISE YOUR PRICES !!!! :

Thanks Kevin! You actually busted me, updating the site is something I`ve been intending to do for a while now, I just haven`t taken the time to do it.



I will agree that the prices/services on the site are really in need of updating as well, since most of the work I`ve been doing lately is a far cry from what is on that list and it is extremely rare that I ever charge the "starting" prices you saw there.



At this point I`m waiting on a couple of projects I have in the works to pan out, then I`ll have enough fresh material to overhaul everything. :smile:

[Kevin Brown]

O-kay.



Some diagrams that may help, and more discussion.

This one compares a long block to a short and long stroke sander.

If you want to see a clearer shot of it, I have a pdf version on my site:



Machine Stroke- How It Affects Sanding and Polishing Performance



The diagram is on page 9.

I don`t usually link it because it is a site that sells stuff.

MODS- if I am not supposed to put a link, feel free to remove it.



The type of backing material a sheet or disc features can also affect leveling.



To be clear, the backing is the piece of material that the sanding media is attached to.



Several types of backing materials are used to make backings for discs, and the type of material is a BIG deal in terms of how the disc performs.



In general... if we have two discs featuring identical backings, except one has a backing that is thicker than the other, and we are using a backing plate that is soft and cushiony:



The disc with the thinner backing will level to a lower degree, but contour to a higher degree.

The disc with the thicker backing will level to a higher degree, but contour to a lesser degree.



The harder the backing plate, the less of an issue backing thickness becomes.



Now, here`s where things get a bit tricky.

Some discs feature a piece of foam placed between the backing material and the attachment material. Most times, the foam increases contourability at the expense of leveling ability. But really, the characteristics of the sanding disc`s backing determines how much an effect the foam has on sanding.



Super thick and stiff backing?

The disc may flex well, and follow curves and complex panel shapes, but it may not contour to every nuance of the surface, such as orange peel.



Super thin and pliable backing?

The disc may follow every nuance of the surface and follow curves and complex panel shapes, but may not level the paint surface.



What if machine speed is maximized?

The effects of foam may be minimized.



Check out these discs featuring foam:



Mirka Abralon:

Tremendous contouring ability, wide range of grades. These are a kick to use, can be used at high or low speed. for me, low speed is better because the sanding pattern is smooth, and the abrasive particles stay attached to the disc longer. Higher speed offer a tiny bit more leveling, and can keep the disc cleaner, as rotational forces fling debris from the disc more readily than slow speeds.

Magnified shot:

Mirka Abranet Soft:

Excellent contouring ability at low speed, fantastic leveling ability at high speed. Compared to discs that use paper or film backings, the net material allows water to pass through (like treads on a tire. So, you can sand with water, use higher speed if desired, yet hydroplaning is not an issue.

Magnified shots:

Meguiar`s Unigrit 3000 Foam Finishing Disc:

Unmatched finishing capability... it`s like having thousands of super soft abrasive squeegees gliding across the paint! Virtually no ability to level, but at this point, you should be refining the surface to shorten buffing time rather than worrying about additional leveling.

Some diagrams comparing film, net, and cloth backed discs. These are also on my site, and are clickable.

About film or paper backed discs:

Film or paper backed discs generally feature maximum leveling potential, but when used with water, they tend to float or hydroplane rather easily. This leads to inconsistent sanding results, as some areas may be sanded perfectly while others are barely affected by the sanding disc. Once the water is displaced, the disc, oftentimes spinning at a rapid clip (due to a lack of frictional resistance) makes a crash landing atop the paint surface. This leads to pig-tailing, gouging, or scouring.



I hope this info didn`t miss the mark, or stray too far from it.

I find this all to be so interesting, and there are lots of things to consider.



The biggest thing that limits our ability to use hard-backed backing plates has to do with user technique. If while sanding we happen to tilt the machine even slightly off kilter, the edge of the disc can dig into the paint. This can create some pretty dastardly sanding marks, especially if we`re using coarse grades of discs. That`s why most backing plates made for sanding discs tend to be soft and pliable.



Now... think you`re pretty good at handling a machine?

Why not make your own backing plate/interface pad combo?



Get a stiff backing plate, and attach a foam interface pad to it. Then, get ahold of a piece of Plexiglas, cut it to the size of the disc, and attach Velcro® hook material to both sides. Slap on your disc of choice, and get to sanding!



The foam interface would help to minimize user-applied tilt variances, so if you happened to get the machine a bit off kilter, the interface would compensate for it. This setup would be ideal for flat panels, but terrible for curved or complex shaped panels.



That`s all I`ve got! For now...