Heavy cut compound discussion / help

dcjredline

dcjredline

New member
So the dealer I do a lot of work for has brought me 2 cars lately that were wet sanded. The first was sanded with 2000 grit wetsanding. I tried my Mothers Heavy Duty Rubbing compound with Yellow flat cutting pad and was NOT impressed, had to slow hand speed way down and do 3 section passes 2x each section to get all the dull out. Friday he brought me another one and this time he wetsanded with 3000 Meguiars Unigrit. This time the Mothers HDRC did 50% better but there were still spots it didnt get the first passes. :wacko: It has a 10 of 10 cut rating on the Autopia Compound and polish chart. I dont get it.

When I have used it on paint that wasnt wet sanded I have been fairly impressed by it but it not being able to cut through 2000 and now 3000 sanding marks is VERY DISAPPOINTING to me.,

I also have a boat here for oxidation removal and I started that with the McKees RV Heavy Cut Oxidation remover. Here is the thing I noticed

The Mothers is VERY liquidy and there is barely a grit feel to it between my fingers, The McKees is an almost toothpaste consistency and the grit was very noticeable. Both shaken VERY well and the bottle of Mothers is probably at least 1 year newer than the McKees.

Anyone have opinions on this AND anyone have a recommendation for a HEAVY compound that is thick and gritty and actually works well in situations like this? I see compounds rated to remove 1500 and 1200 grit sanding marks and I highly doubt that this Mothers will.
 
dcjredline said:
Sorry, this work is being done with my FLEX 3401 also. Left that part out by accident
Click to expand...

Hello, Don !
Hope all is good with you and your family !

For any type of wet sanding scratch removal, the only thing that I have ever found that took it out is Rotary Power with Meguiars 105, and Lake Country Purple Foam Wool pads - a lot of them..
Meguiars 105 will actually finish down really well, if you can get it past the "Im going to dry up immediately and try to ruin your work" part.. And it is easy to get it past that by just spraying a little moisture on the pad and mind it while you are doing the work. Keep on adding just enough moisture as needed, to allow the compound to almost go away completely.

These L/Country Purple Foam Wool pads will only last so long ( they will go flat and not fluff up any longer), and then you have to toss them and get a new one out.. They are made to work this way... You will be able to tell when they no longer change the paintwork they were just used on...

I have used this same process and products on very dirty, harder than granite, Urethane Airplane paint (2 different colors), and while it took an enormous amount of hours, it took the airplane paint to a beautiful, pretty clear, and very glossy state, ( M105, and M205 with White Flat Foam), that the Owner could not believe when he saw it again.. He was so excited that we pulled the airplane out of the hanger so he could take pictures of it..

Regarding Boats, the absolute best Boat Detailer in Seattle WA., and surrounding areas, uses nothing but Rotary Power and heavy compounds to knock all that stuff off that sticks even worse to gelcoat... I have seen his work on jet black boats and they look every bit as good as what I can achieve on jet black automotive paint.. :) He routinely kills DeWalt Rotaries every year from this hard work, and lucky for him, he has helped DeWalt design better quality Rotaries for this application, and they give him a break when he sends in the the dead ones, on new ones...
Any random orbital would never last very long trying to Detail gel coat... He laughs when companies send him random orbitals to test out.. :)

Gelcoat takes even longer to correct than automotive paint... I will never want to detail boats!!! :) Or anymore Airplanes! :)

Later on but still a while back, Meguiars came out with Meguiars 101, which is similar to M105, but made specifically for Foam Pads, used in Europe...

Eventually, Meguiars made M101 available in America; this might also be a great option to try... Here is a link for it -- https://www.autopia-carcare.com/meguiars-foam-cut-compound.html#.W5X8U1WpH3g

Coming from the auto painting world as well, we used nothing but professional products; back then it was all 3M products to get similar results with all types of automotive paintwork in all the different conditions we found it in...

I have had a Flex3401VRG since they first came out! I immediately cut down the 6" backing plate to work with 5" pads and that alone helped, but it will never be able to put down the power of a direct drive rotary.. As I remember, the marketing for it was that this machine will give you rotary benefits and random orbital benefits, to help one never have to deal with rotary holograms, etc...

I tried it to see what it would do, and it would handle minor paintwork issues pretty good, but nothing like a direct drive can accomplish... It has been having a long, long, vacation, in the machine cabinet.. :)

Well, in my 50+ years of holding 10lb Rotary machines, , I have never had issues with creating all those rotary "defects" people talk about all the time anyway..:)
It is all about keeping the pad, product, and paintwork just moist enough so all 3 can have a nice time together, knock out the needs for that spot, wipe it off, and move on...

Keeping speeds below or right at 1,000rpm also helps these 3 key elements (Pad, Product, Paintwork) working together nicely, until it is all broken down, the pad cleans most of it all up, and all you have left is very little to wipe off, thereby eliminating another source of adding more defects to the paintwork...

This is exactly how I was taught as a 10-year-old boy, and the same lessons were reinforced by some really great painters, throughout my life, until I went out on my own, and then taught others who were new to the business..

Don, you may find your own "technique" to arrive at the same place be different than mine, or anyone else`s, but I can promise you, the basics for the 3 elements above, (Pad, Product, Paintwork) really need to be able to get along nicely, and when allowed to, you will always see great results..

Sometimes, I have had to lean a little harder ( I always put pressure on it) on some defects in paintwork to help the process be more efficient, and quicker, and that is ok too, as long as you mind the total paint thickness of that spot, the type of paint - soft, medium, hard, very hard, granite, etc..., and how much heat you are creating... Strive to keep the heat down, let the spot cool off if it got too hot.. Look it over very carefully, do not let it get "sticky"..

So, you may need to consider using a direct drive Rotary to really knock this stuff out faster and give you incredible, beautiful, clear and glossy paintwork..

Wish I was there to help !!!
Dan F
 
Can`t speak to sanding marks, but M101 using a Boss 15 DA and Griots Boss Microfiber got through some deep scratches and scuffs on `hard` black Mercedes paint no problem. I like Stokdgs suggestion to add a little moisture to extend working time, ease removal and I bet it controls dusting a bit.

I don`t compound often, so I don`t have some of the newer formulas, but the way M101 gets through stuff, I really don`t need to shop.
 
Rotary + Wool + Meguiars M100 is the friend you need. I don`t ever plan on using a DA to remove sanding scratches.
 
Thank you for the specific post Dan. And thank you everyone else. Looks like I will have to bust out the rotary. I was hoping there was something I was missing. And I will have to price those jobs to go around the vehicle 2x instead of once.

Not the news I wanted but the news I needed to hear.
 
You may wish to try Jescar Correcting Compound with a wool pad on your 3401.
M101 is another favorite compound and (although designed for foam) works well with a wool pad on a 3401.

You will need to follow up with a polishing pad and a finishing polish. I suggest trying Jescar Micro Finishing Polish.
 
dcjredline said:
Thank you for the specific post Dan. And thank you everyone else. Looks like I will have to bust out the rotary. I was hoping there was something I was missing. And I will have to price those jobs to go around the vehicle 2x instead of once.

Not the news I wanted but the news I needed to hear.
Click to expand...

Mi Amigo, Don !
You are welcome ! I am sorry its not going to be easy - but - it will be worth it to just knock that stuff out and as has been advised by some of the BEST guys out there, come back with your Flex 3401VRG and it will be very fast and easy to remove anything left in the paint to totally bring the clarity and gloss out to an amazing level..

You are in total control of exactly what level you want to end this all at, I am positive, the results will be stunning to the Client... :)
Dan F
 
Oddly enough, I was planning on making a thread for a recent combo I did over the weekend. Hopefully, I can do it today.

At any rate...

On a softer-side OEM Toyota Yaris paint:
- a bit of damp sanding with 2000 grit
- compound with CarPro FLASH pad
- Menzerna FG400
- Flex 3401

In just two passes, I got good results. I later went back to clean up parts I missed with those two passes. Got rid of the sanding marks, and finished well.

Like i said, I`ll try and do the thread (with pics) today.
 
I use the 3401 with M101 and just do as many passes as it takes. I`d probably ly at least consider resanding 2K with 3-4K, I don`t like working 2K scratches.
 
Could it be that they sanded before with a lower grit sandpaper? So they did not sanding down the first sanding enough. Or the defects before they started sanding was to deep to be sanding down.

I think that I would test with a different pad and compound first. Lake Country does a thick and a thin purple wool pads that works on DA polishers. Combo them with your 3401vrg and a heavy cut compound. Maybe your Mothers compound can have the cut to get where you are expecting to get. Sonax Cutmax and Menzerna SHC300 and Carpro ClearCut I think would give you the cut you want. The Meguiars m100 or m101 you have the benefit with SMAT abrasives so you can work it for a long time. Just some suggestions before investing in a new rotary polisher. Or you maybe have a rotary already? A rotary would get you the high cut and working faster. But I think that your 3401vrg would handle to polish out p2000 sanding marks quite easy with the right combo of pad and compound.
 
JustJesus said:
Oddly enough, I was planning on making a thread for a recent combo I did over the weekend. Hopefully, I can do it today.

At any rate...

On a softer-side OEM Toyota Yaris paint:
- a bit of damp sanding with 2000 grit
- compound with CarPro FLASH pad
- Menzerna FG400
- Flex 3401

In just two passes, I got good results. I later went back to clean up parts I missed with those two passes. Got rid of the sanding marks, and finished well.

Like i said, I`ll try and do the thread (with pics) today.
Click to expand...

Ill check the thread later thank you. Ive done MANY MANY spots or panels that were wet sanded with really good luck. There is a HUGE difference between doing a spot/panel to the whole stupid car lol. This last car was an 11 Cruze there are many contours on those and cutting those are the worst part of it. Thanks again for the comment, I will get some before and afters of the boat for everyone.
 
Ok, a little update.

1. I wasnt using enough product
2. Even with a wool pad and rotary the results were minimally better cause the gelcoat was in bad shape.

Looks like photo gallery is STILLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL not working.
 
Accumulator said:
I use the 3401 with M101 and just do as many passes as it takes. I`d probably ly at least consider resanding 2K with 3-4K, I don`t like working 2K scratches.
Click to expand...

I have an easier time removing 1500 grit scratches than 2k unless it`s a small spot.

I did the hood on a black 2018 Equinox a couple weeks ago that our body shop pushed out too quickly and had a ton of solvent pop.

I sanded the hood with 1500 by hand and then 3000 trizact with the da and buffed it out with a wooly and 3 m perfect it steps 1,2 and 3,,step 2 with a black foam pad and step 3 with a light blue pad,,all 3m brand.
 
Farmall-luvr- Ah, Perfect It! Heh heh, didn`t think anybody remembered that line :D I liked the PI-III, but none of their other variations.

I`m confused! Why would it be easier to remove 1500 than 2K?!? The scratches are deeper, so you have to remove more to make it level, so you`re doing more work, and to *me* that makes it harder. Gee, I haven`t tried to take out 1500 since...man I don`t know!...maybe the `70s, back before we had decent high-grit papers (let alone sanding disks).

I note that you follow 1500 with 3K, which seems contradictory to the above...I`m sure not trying to argue or anything like that, but I am confused :D

EDIT: Oh, and Welcome to Autopia! Don`t think we`ve shared a thread before..
 
I use the Perfect II ,,I use 2000 too,, but I`d rather sand less and buff more and it takes me longer to sand some imperfections out like runs and dirt with 2000 than 1500 and I hate using 1000 or even 1200.

as for the wet sanding solvent pop with 1500 by hand and moving up to 3000 trizact DA that was suggested by one of our body guys ( the one I don`t have to fix stuff behind) it worked,,normally I would go 2000 and then the trizact ,,plenty of clear to do it.

plus the owner the dealership is a tightwad and won`t buy trizact,,we sneak it in
 
When these compounds all claim 1200 grit capability I figured I could breeze through 3k sanding marks. Thats my main disappointment
.
 
somtimes I find that I move too fast for the compound to be effective or use not enough product,,,if I gotta go over it a couple times I`m ok with that,I get less arm pain buffing than sanding :)
 
You must log in or register to reply here.
Back
Top