Wet sanding with Flex 3401

[piperchris]

This is a hypothetical question. Can the Meguiar's 6" Unigrit sanding disks be used safely with a Flex 3401 VRG? I read on Autopia they can be used with a pneumatic D/A and the G110 but not anywhere does it talk about a Flex D/A. If it will work safely, I wanted to start learning to wet sand (I don't care about the paint on it I just only want to learn only if it will work in general) on my car that's totaled before it goes to the junk yard.

[Markus Kleis]

Re: Wet sanding with Flex 3401

Meguiar's won't have an official stance on this because it is using a third party's product, but if the car is totaled anyway...what do you have to lose?

[J. A. Michaels]

Re: Wet sanding with Flex 3401

I think that since the car is totaled and going to the jun pile. That it would be a worthwhile experiment. I would say, go for it. Then let us know your findings.

[TH0001]

Re: Wet sanding with Flex 3401

If you put a piece of tape on the backing plate and turn the machine on (facing you at low speed) you can see the pattern the machine moves the backing plate. It makes a very tight 'inverted' curly que pattern, similar to walking in a curved line, stopping, pivoting 270 degrees and continuing in a new curve. Only you are not digging your heel in, you are grinding any loose abrasives and removed paint into the paint.

The pattern the Flex creates is too tight and (IMO) does not lend itself well to DA sanding. Because the pad will stall and make a tight turn (instead of looser curly q's) you have an increased risk of creating pig tails.

Also the forced rotation will cause the pad to bunch up over curves (instead of stalling as on a Random Orbital) which could make for some deep and interesting marring on curved body panels.

If you are going to attempt to sand with a Forced Rotation buffer I would absolutely use an interface (soft foam backing) between the backing plate and the sand paper to mitigate the grinding effect of the forced rotation and stick to fairly flat body panels. Stay away from anything more then a gentle curve.

[Michael Stoops]

Re: Wet sanding with Flex 3401

Fantastic advice, Todd!

There are reasons that D/A sanders are used and not rotary sanders when working on automotive paint. Even the throw of a D/A sander will impact the cutting ability of the abrasive media, let alone the speed and pressure applied. But as Todd points out, the motion of the Flex just doesn't lend itself to sanding as it can cause some pretty serious issues. The really disconcerting about it all is that you may find in some quick testing that everything seems to be OK but in the real world (ie, on a car that means something to you or someone else) things change rapidly.

There is an expectation of success, so to speak, built into every product on the market. By that we mean each product is designed to be successful in the vast majority of cases where it is used (as intended) even with all the variables that can be present. Even the "best" product will fail under certain conditions, and even the "worst" product will succeed under certain conditions. But a product being used in a way it was not designed to be used is like throwing darts in the dark. Sure, you might your target every now and then, but in this case the target keeps moving and your throws become even more random.

[Mike Phillips]

Re: Wet sanding with Flex 3401

Just by chance, I tested this idea for a forum member with the same questions...



Can the Flex 3401 be used to wetsand?

Yesterday our forum member weecho asked in my thread here,


[quote=weeecho;812936]

hi there, i was wondering why did you don

[Turboelky]

Re: Wet sanding with Flex 3401

I tried it with a 5000 grit disk. It worked a little bit with the flex, but much better with a standard rotary. Don't waste your time on that.