i bought a porter cable and used it the other day to polish a slight scratch out of my hood. I am using meguires pads that are 6.5"

I was using some 3m perfect it foam polishing glaze but that wasnt doing much so i changed pads and used the 3m perfect it iii extra cut rubbing compound and that got most of it out.

my question is the speed of the 7424 xp. the compound said to use 1800-2400 rpm. the instruction with the 7424 says this is the #1 to #2 setting on the tool. but the pad was just kind of ratcheting back and forth and not doing much. i ended up putting the setting up to 4 or 5.

any advice? do the speeds listed on the polishes and compounds valid for dual action polishers?

what setting do you use with the 7424 xp?

Those RPM suggestions are for rotary polishers. For a DA the ratings are measured in "OPM" (orbits per minute). .....definitely not comparable.

While I don't own the PC7424XP, I do own the older version (and a Flex3401VRG). Personally, most of my correction is done at or near the highest setting but I will use the lower speeds initially to help spread the product (reducing the chances of sling).

thanks! that what i was thinking. cause the tool doesnt really do diddly squat at the low settings!

thanks! that what i was thinking. cause the tool doesnt really do diddly squat at the low settings!

The head of the PC7424XP (like many other DA's) are a forced orbit but the rotation is clutch-like. In other words, if you add too much pressure, too slow of a speed and/or cause too much friction from larger pads, the rotation of the head can stall/stop. Essentially, all the head will do is simply “jiggle” in place. Sometimes this isn’t always apparent so adding a vertical line (with a Sharpie) on the backing plate can help you see whether you’re having an issue (so you can adjust speed, pressure, try a different pad size, etc.). Some DA’s like my Flex 3401 have both a forced rotation and orbit so there is no stalling. ….but it can be a bit of a handful at times.

IMO/IME, there are reasons you may want to use lower settings at times for other tasks but realistically you'll likely find yourself staying within 3-6. ....~3 to spread and 5-6 as your highest speed for correction. You may want to do some searches on detailing forums like Autopia.org, Autogeekonline.net, Detailingbliss.com, etc. to get a feel of what others are doing/experiencing. Keep in mind that there are a variety of other factors involved that may play a role as well.

I recall some issues with bad backing plates (separation of the hook & loop pad) but I think that is mostly in the past. I believe most manufacturers have caught up with the stresses/demands these more powerful versions of the DA put on their products.

Something else to think about is that higher speeds, pressure, etc. can also put more stress on the pads you're using. It's always a good idea to periodically check your pad, backing plate, temp of the panel, etc. so you can identify any potential problems before they result in some sort of failure/damage.

Hope this helps.



….btw, I don’t know if it still holds true today but some of 3M’s compounds (at least at one time) contained silica based abrasives. Ideally, you don’t want to breathe any sort of product dust into your lungs but silica is apparently some nasty stuff. If it gets lodged in your lungs it apparently doesn’t dissolve and is carcinogenic. I stopped using my old bottles of 3M polishes after I found that out and began wearing a mask whenever using any of my other polishes (supposedly safe or not). ….I wasn’t particularly “wowed” by my Perfect-It and Finesse-It polishes anyhow so it wasn’t any loss. I only used them a handful of times years ago but I would have certainly been worried if I had been using that stuff every day for an extended period.

….ear protection is also not a bad idea.

thanks again. ive learned a lot from your posts on here and the links you supply have a ton of information- sometimes so much i dont think i have enough time in the day to read them all!

....no problem. I'm glad you found it helpful.