My experience with menzerna 300

Hi everyone.

I worked on a 2018 mustang with (what I assume is) hard paint over the past few days. I was trying to decide if I wanted to do menz 1000 + 2500 combo as I have experience with those two and hard paint (at the sacrifice of finishing gloss) or try my new bottle of 300.

Initially I believed I was still going to finish with 2500, in anticipation that haze would still be left over if I used something from the 3000 series. After doing a test spot with 300 and 3500 (and 1000 + 2500) I was pretty surprised at the results - given that I used a lake country orange pad with the 3500 (yellow pad with 300).

Even more so with how 300 was able to initially cut as an effective compound for the hard paint and break down to a point that would allow for 3500. I did notice that for this to happen there had to be pressure and speed adjustments towards the end of the buffing cycle.

Here's a short video that shows what I did:

YouTube

Rupes LHR 15
LC yellow pad
Speed at 4
Moderate pressure

First clip I used 5 passes at consistent pressure and speed. Second clip I used that same pressure and speed, 4th pass decreased to speed 3 with same pressure, 5th pass decreased to speed 2 and decreased pressure slightly.

I noticed no difference in cut between both areas. Both were done on same panel.

However, I wasn't able to get same correction as I would with 1000 + 2500. I suppose there's the give and take with jobs like these (unless if we 3 step).

Any suggestions on working 300 differently? Or perhaps products similar to 300 that would cut a bit longer? TIA!

I have not used it myself the SHC300. But it's a deminishing abrasives in it. So you always have the most cut in the first pass and then it decrease with the passes you do. And also since I think it's a newer compound than the HC1000. The deminishing abrasives breaks down faster but also cuts faster.

Give it a go again and try something like this.
First dab out the compound on the section you are compounding. And if you want to spread it out with the polisher on after this. Do it on the lowest speed setting and do it fast and with only 1 pass and turn off the polisher. Turn up the speed setting to around 4 and just a little extra pressure on the polisher so it don't boggs down the spinning part (mark your backing plate so you easly see that your have pad rotation). Use a slow armspeed of a inch per second. Crosshatch pattern/2 passes and 2 more passes with only the weight of the polisher and same armspeed. Wipe the residue off and clean the pad with an air compressor or brush. And if you still don't get the results you want in the cut. I would move up to a Lake Country Low Lint Wool Pad and the same technique. Some use a higher speed setting and pressure so you get the more pressure and the pad rotation boggs down to as you would have it on a lower speed setting. I think that it gets to hard to polishing this way and use rather a firm pressure that don't gets to heavy to keep up with on the whole car.

The part with the deminishing abrasives and it breaks down faster now days. You may get away with 1 slow armspeed pass with slight pressure and 1 or 2 more passes with only the weight of the polisher and the same 1"/second armspeed. That's also why if you spread out the compound with a speed setting of 2-3 and 2 passes even with a quite high armspeed. You have already done and used the high cut ability from the compound. If you keep doing the extra passes in the end it will not cut so much as you are on the smaller refining abrasive part. Say that you have been close to getting satisfied with the results from the cutting you can get the extra little cut with 2 more passes or something like that. I would test out to just do 1 pass and stop and wipe it off and inspect the results you get from just that. And you can try 2 passes with faster armspeed and see if you get any difference in the cut. And then test where you have got the smaller abrasives to do it's work with cleaning up the haze/micro marring from it. When you get to know more about the product and how you can dial in it to getting the results you want.

Rupes has DA wool pads also if you want to give those a try. Then the Lake Country Low Lint Wool Pad and the Purple Foamed Wool Pad is great too. You have also the mf cutting pads to go with. If you want to try another compound with a high cutting ability from it. You have the 3D ACA 500 X-tra Cut Compound which I think is a non deminishing abrasive compound or the Sonax Cutmax that cuts and finishing very good. But with dial in the technique and how you like to do with the different ones. Menzerna SHC300 is a great compound. Sometimes the foam cutting pads is not aggressive enough and you need to be stepping up to the mf cutting pads or wool pads for DAs.

And remember that you have the highest cut right from when you start the polisher with compounds like Menzerna SHC300 and Sonax Cutmax and Carpro ClearCut. And the extra passes in end is to get a better finish that your finishing polish can handle with the least aggressive finishing pad you get away with.

/ Tony