MT300 question on spinning

[gkbailey78]

Re: MT300 question on spinning

It is critically important, with any random orbital DA polisher, that you keep the pad flat against the paint in order to maintain pad spin. The MT300 is a torque monster and with the pad flat against the paint you can almost stand on it and still keep the pad rotating. Of course, that's when the tool is set at 4800opm or higher, as lower speeds don't provide the same level of torque (that should come as no surprise to anyone since this is basically true of virtually any type of motor running at lower speeds/lower amperage). Then again, lower speeds are generally used for things like finish polishing or wax application and torque is not really needed for those applications. But if you're correcting defects, you should be running at 5800opm at least, and at that point the MT300 is just loaded with torque. But, just like any other random orbit DA, as soon as you start leaning on an edge the rotation will stop. Working on a curved surface can mimic putting the tool on edge, so convex surfaces should be treated by keeping the center line of the pad in contact with the panel as shown in the video below. Note that at roughly the 00:11 mark I lift my hand off the tool momentarily and then I put it back, using pretty significant pressure. The pad continues to rotate.




When working on primary panels, while it's true that you very rarely find a totally dead flat panel on any car, you still want to keep the pad essentially flat against the panel. But as the panel curves you need to move the tool to mimic that curve in order to maintain that full contact. On this car, the hood sloped down at the front and to both sides. The tool can not remain parallel to the ground, but parallel to the hood. We see people doing the former during many Saturday classes, primarily because they tend to tense up a bit when first using the tool. When they tense up, not only do they not follow the contours of the body panels, but they tend to lock their upper bodies so that when moving side to side they sort of pendulum at the waist, and the tool arcs over the paint instead of staying flat. Again, they lose pad spin on the extreme sides of their work area when doing this. In the video below you can see that I actually cause a deformation of the hood due to the pressure I'm using, yet the pad never stops rotating. And I'm using pretty significant pressure here. You can also see how small the work area is, and how slowly the tool is moving across the paint. In some cases you may want this work area to be even smaller, and the speed across the paint even slower.

I am currently using the microfiber system (D300-302) with the MT300 on my son

[gkbailey78]

Re: MT300 question on spinning

I am currently using the microfiber system (D300-302) with the MT300 on my son

Sorry, I somehow messed that up. I

[Michael Stoops]

Re: MT300 question on spinning

Sorry, I somehow messed that up. I

Any chance you're composing in Word and doing the copy/paste thing here? The forum software hates that, and special characters will break the thing and truncate your message at that character. I'm guessing the odd apostrophe here and there is doing you in. Sorry about that. For the record, the text box here is the best way to go - it even lets you italicize, bold, change fonts, etc if you like.

[gkbailey78]

Re: MT300 question on spinning

Any chance you're composing in Word and doing the copy/paste thing here? The forum software hates that, and special characters will break the thing and truncate your message at that character. I'm guessing the odd apostrophe here and there is doing you in. Sorry about that. For the record, the text box here is the best way to go - it even lets you italicize, bold, change fonts, etc if you like.

Sorry about that, I was trying to reply over my iPhone. Maybe that was the issue. Anyway, I worked on my son's black VW Golf with the MT300 and microfiber system. I used the D300, D302 and then the D301 finishing wax with the appropriate discs. However, there are still several swirls which I didn't think would be too hard to get rid of. I'm wondering if I'm not using enough pressure. My questions is, how fast should the backing plate be rotating? I read somewhere that its around 1 second but that doesn't seem fast enough. How often should I see the white marks turn over? I'm hoping that is the cause of it not bringing the corrections I had hoped for. This is my first time using a DA polisher so the chances for user error are pretty high. Thanks in advance!

[Nick Winn]

Re: MT300 question on spinning

Sorry about that, I was trying to reply over my iPhone. Maybe that was the issue. Anyway, I worked on my son's black VW Golf with the MT300 and microfiber system. I used the D300, D302 and then the D301 finishing wax with the appropriate discs. However, there are still several swirls which I didn't think would be too hard to get rid of. I'm wondering if I'm not using enough pressure. My questions is, how fast should the backing plate be rotating? I read somewhere that its around 1 second but that doesn't seem fast enough. How often should I see the white marks turn over? I'm hoping that is the cause of it not bringing the corrections I had hoped for. This is my first time using a DA polisher so the chances for user error are pretty high. Thanks in advance!

Welcome to Meguiar's Online. Below is a video for reference. Especially with our DMC3/DMC5/DMC6, it does not take a really fast rotation to still achieve cut. I would guess Mike is running the machine at 4800 opm or 5000 opms in the below video. Hopefully this is a good start to your question.

[Michael Stoops]

Re: MT300 question on spinning

Sorry about that, I was trying to reply over my iPhone. Maybe that was the issue. Anyway, I worked on my son's black VW Golf with the MT300 and microfiber system. I used the D300, D302 and then the D301 finishing wax with the appropriate discs. However, there are still several swirls which I didn't think would be too hard to get rid of. I'm wondering if I'm not using enough pressure. My questions is, how fast should the backing plate be rotating? I read somewhere that its around 1 second but that doesn't seem fast enough. How often should I see the white marks turn over? I'm hoping that is the cause of it not bringing the corrections I had hoped for. This is my first time using a DA polisher so the chances for user error are pretty high. Thanks in advance!

Welcome to Meguiar's Online. Below is a video for reference. Especially with our DMC3/DMC5/DMC6, it does not take a really fast rotation to still achieve cut. I would guess Mike is running the machine at 4800 opm or 5000 opms in the below video. Hopefully this is a good start to your question.

The video Nick posted also shows some other points regarding technique that many new users miss - very slow arm speed across the paint, and a small work area as is clearly seen by the product residue on the paint. Pad rotation is probably more critical than pressure with a lot of paint systems, but you always need to experiment. Historically, the thinking has been if you need more cut you need more pressure, more tool speed, or maybe both (along with possibly a smaller work area, different compound, pad, etc). But that whole "more pressure" thing tends to get people, and equipment, in trouble. You see, while it's true that as long as your pad is spinning, even slowly, you're still cutting that does not mean you should just stand on the darn tool to get more cut. That ends up super heating the hook and loop material that holds the pad/disc to the backing plate. This is the stress point, if you will, with a DA polisher. Simply put, it's a violent place to be! That oscillation is trying to throw the pad off the plate all the time, and the friction is immense. So much so that, in extreme stress testing here, I hold the record for most heat generated at the pad/backing plate interface (inert gentle pat on the back here).

310 degrees F.
In 2 minutes.



Now, it takes more than 2 minutes to buff out an entire car. And 310F is almost hot enough to cook a chicken, given enough time in the oven. It's also hot enough, given enough time buffing, to literally melt the hook and loop material and fuse the pad to the plate. Or cause the adhesive between the loop material and foam to fail and delam the disc. Other bad things happen to the equipment as well, even the paint doesn't necessarily get all that hot.

So, let's not go nuts on the pressure. instead, ease off the pressure a bit to gain pad rotational speed. Keep the arm movements nice and slow and let the pad/disc move the abrasives in the compound around more. Let them tumble and do their job. Keep the work area small, the arm speed slow, the pressure moderate at best for lots of spin, and keep the tool speed in the 4800~5000 opm range that Nick stated above.

Let's talk about the big variable in this whole thing though - the paint. VWs are known for having pretty hard paint. Not all of them have such hard paint, of course, but this brand is notorious for having hard paint that is slow to correct. If your son's Golf is indeed one of them, then taking your time and letting that pad spin a bit more quickly with just some nice, firm pressure is probably the better approach. It's also possible that D300 isn't quite potent enough for the task at hand and perhaps M100 or our brand spanking new M110 (oh yes, please!!!) is the ticket. M100 will give a noticeable lift in cut over D300, but with some added dust. I've got a '74 Alfa Romeo Spider at home with extremely hard paint that I wet sanded and buffed out using mostly M100 on microfiber discs with the MT300. It came up great, but it needed that extra bit of cut as I was pulling out sanding marks. But I never got crazy with pressure on the tool. Firm and solid pressure, yes, but lots of pad spin too.

Technique is a funny thing, and tricky to nail down as the variables are almost infinite. And the exact same technique doesn't work on every car as the paint systems are also almost infinitely variable. That's why nobody makes that perfect secret weapon of compound or pad that works 100% on every car every time. User skill is what really makes or breaks a detailing session. And as with any other intricate process, that skill set takes time to develop.