New to refinishing, and alot to learn

[rotormotor]

Hi everyone... im currently trying to sort out the paint on my old 67 MGB. its been repainted once (somtime in the 70's) and has sat for years. the car is now running again but has horrible oxidaition on the surface, and hatch marks in the paint. the good news is the past time it was painted they went rather heavy on the paint so i have a good amount of material to work with. just for fun i hand wet sanded the fender to see what would turn out. i started with 800, then 1200, then to 1500, and finally applied by hand some generic rubbing compound. after that some meguires n-tech wax just to see how it would look... and it turned out GREAT. so ive come here for some assistance with the rest of the car.

yesterday i bought a milwaukee rotary buffer, and some 7" pads... unfortunately i think they were too thin as i hit the surface of the paint with the retaining nut on the rotary... i have 1" pads which are probably too thin for this application. anyway long story short i wanted to get some more info on how exactly to proceed with the tools i have.... and what pads, products, tools i still need to buy in order to do this propperly.

i dont know much, but am willing to learn.... so please bear with me asking "stupid questions". im off to do some searching on the forum to try to piece together the process/compounds/tools that ill need.... but any recomendations for tools, products, or step by step procedures would be greatly appreciated. again i appologize for being a newb. -heath

i can post pictures if that helps in determining what road i should take with bringing this paint back from the dead.

[MB///HRV]

Let's see the pics. They truly are worth a thousand words.

[the other pc]

Hi Heath, to MOL.

First, if I may paraphrase our local SWAT team,

PUT THE BUFFER DOWN AND BACK SLOWLY AWAY FROM IT WITH YOUR HANDS WHERE WE CAN SEE THEM.

Sorry about that, but a rotary buffer, especially a beast like the Milwaukee, is a very power tool and can destroy a finish very quickly if used incorrectly. The mantra for learning the rotary is to never practice on a car that you don't want to make irreparable mistakes on. I guess if you're willing to spring for a new paint job there's nothing to lose by trying it.

If you really want to learn how to use it (and outfit it) properly this is a great place to start but it's best to begin with less advanced techniques.

So, let's see some pix of the B.


PC.

[rotormotor]

hahahahaha! seriously, after using the rotary for a minute and a half i did set it back down on the floor and walk out of the garage. ive left a few marrs on the paint already. but honestly, the only reason im even bothering with trying to buff it is to be able to drive it for a year or two before having it repainted in a full body off restoration. i could concievably send it in now, but ive been working on the poor car so long it would be nice to enjoy it for a year or two before going back under the knife.

anyway, yes... this is a "practice car" and i have a second practice car as well to work with... a friends 92 civic with a peeling clear coat. hopefully by the time im done with those two ill feel comfortable enough to polish, wet sand, or apply some of the skills that ive learned to the finish of my cherished rx7 .

so to start heres a picture of the car "before" ... ill post a few of the hatch marks, oxidation, etc next.

[Murr1525]

Looks like it needs a good wash... but should be fun to drive once you have it all fixed up.

Are your other cars in this shape, or detailed more frequently? You may want to start your experience with machine buffing by trying out a G-100, and it will serve you well even after you learn the rotary as well. The G-100 is much milder, so wont fix the major problems, but can handle smaller things like swirls, small scratches. And is just about risk free even for your more prized cars.

Rotary vs. PC vs. Regular Orbital Buffer


Recommended Products - G100a Dual Action Polisher

[rotormotor]

heres the right fender done by hand... wet sanded from 800->2000 then rubbing compound then wax.


unfortunately i couldnt capture the hatch marks with my camera on the other body pannels... but i had to remove a good amount of material before they dissapeared.

i sanded and lightly polished the hood by hand (front bit with the milwaukee) but i should have sanded longer as hatch marks still exist in some areas.



finally... a little carnage from the center metal retaining nut on the rotary... i think my pad depth is too shallow (1") or im doing it wrong...

[Murr1525]

Incidently, since you live in California, maybe near Meguiars, you could try to sign up for one of their detailing classes, either Saturdays, or some Wendensdays. Everyone always learns a lot there.

[rotormotor]

Originally posted by Murr1525
[B]Looks like it needs a good wash... but should be fun to drive once you have it all fixed up.

Are your other cars in this shape, or detailed more frequently? You may want to start your experience with machine buffing by trying out a G-100, and it will serve you well even after you learn the rotary as well.

the rx7 has a bit of orange peel that needs to come down (dont know if that should be wetsanded or simply buffed)... my miata has similar issues (had repairs done on both cars and the finishes that resulted were not top notch).

[the other pc]

Cool! I agree rotormotor, get out there and drive it.

There's a lot of stuff to learn about before revisiting the rotary but since you showed the mounting nut wound I'll chime in with a suggestion now. If you want to keep this machine (there's a whole 'nother discussion topic there) take the Milwaukee pad, mounting plate and nut and throw them away. Very far away. Then get a Velcro backing plate (Like Meguiar's W64 or W65). This is the type that quality minded pros use with the "good" pads.

Which model Milwaukee do you have? (I hope it isn't the fixed speed version.)


PC.


(Murr1525, Santa Cruz is an 8 hr. drive from Irvine, but I've seen guys come from farther...)

[rotormotor]

Originally posted by the other pc
Cool! I agree rotormotor, get out there and drive it.

There's a lot of stuff to learn about before revisiting the rotary but since you showed the mounting nut wound I'll chime in with a suggestion now. If you want to keep this machine (there's a whole 'nother discussion topic there) take the Milwaukee pad, mounting plate and nut and throw them away. Very far away. Then get a Velcro backing plate (Like Meguiar's W64 or W65). This is the type that quality minded pros use with the "good" pads.

Which model Milwaukee do you have? (I hope it isn't the fixed speed version.)


PC.


(Murr1525, Santa Cruz is an 8 hr. drive from Irvine, but I've seen guys come from farther...)

well even though its an 8hr drive i have a few friends that live in southern california so its something to add to my next visit.

as far as the model i have the variable speed version. ill order the meguiers backing pad. which do you recomend... 6.5" pads or 8" ... it seems that the w8000... and associated various pads come in different sizes. are those velcro pads?

also what size is the orbital machine that meguiars produces? how much power do those units put out versus one of the direct drive orbital machines? and where can i order one? sorry im playing 21 questions... im just a bit frustrated with what to do now. -heath

[rotormotor]

oops...forgot to finish my thought in the previous post. *As far as the milwaukee, its the variable speed version, and was $189 at the local OSH.

[the other pc]

Milwaukee makes two variable speed polishers one goes to 1750 rpm, the other to 2800 rpm. Either will work for paint polishing (Meguiar's generally recommends speeds in the 1000-2000 rpm range).

The Milwaukee is an excellent tool, powerful, well made and rugged as heck but it's much heavier (8.8 lbs) than some other machines, like the popular Makita 9227 (6.6 lbs).

You can use either size pad with a rotary buffer. Everyone has a personal preference. 8" pads will cover more area, faster. I think most people find 6.5" pads more maneuverable and easier to control. I'm not the most skilled rotary jockey around. I stick with 6.5", which also work on the G100 dual action orbital machine.

As I said, Meguiar's G100 (same drive unit as Porter-Cable's 7424, 7335 and 7336) uses the 6.5" pads. It draws around 400 Watts (compared to the Milwaukee's 1300 Watts) and is of course a DA orbital, not a rotary. It's far less aggressive than a rotary but also very safe to use on fine finishes. It will remove light to moderate defects but can't handle deep defects or sanding scratch.

Since your paint has sanding scratch and heavy oxidation I would say the rotary is the right tool (perhaps followed with a DA for the final gloss). Using it is a matter of some study and practice, practice, practice.


PC.

[rotormotor]

ok i have the 1750rpm model thats variable. so will the meguiars 6.5" backing pad fit the spindle on my milwaukee? and are all the various meguiars pads (cutting pads, polishing pads, etc etc) velcro backed? im also looking into a g100... and you say that will accept this same pads? im wondering if i really need BOTH the milwaukee and g100... 400 bucks on buffers ALONE (not even factoring in pads, products) is already a serious investment.


PS it looks like i can get a porter-cable 7424 online for around 120 ish... are there any diffences between this and the meguiars unit (which as far as my searches reveal comes in around 175 online).

[the other pc]

Your Milwaukee has the (USA) industry standard 5/8”-11 threaded spindle and should work with Meguiar’s (and anybody else’s) standard backing plates.

Meguiar’s does make some non-Velcro pads for special applications but the real workhorses for detailing, the W7000, W8000 and W9000 8” foam pads, W7006, W8006 and W9006 6.5” foam pads and the W4000 wool pad are all Velcro backed so any or all of them will work with your Milwaukee once you get appropriate backing plate(s).

The G100 uses the 6.5” pads. You can mount the 8” pads on a G100 too but you won’t be able to do any significant defect removal because you dissipate the limited power available from the machine over the much larger surface area.

If you plan to do wet sanding, rotary buffing is pretty much mandatory. There is some debate over whether you need both a rotary and a DA buffer. Some people claim they can reliably get a super high gloss finish with no swirls by rotary alone. I do know that I’m not that good. I have both. The best rotary guys I know also use both.

The conservative approach is to only use a DA polisher and leave the (much less often needed) rotary buffing to experienced professionals. If you’re committed to DIY it’s your call.

The Porter-Cable 7424 is the same machine but you still need to buy a Velcro backing plate and a real buffing pad (the fixed pad that comes with the 7424 is junk) to make it physically the same as a G100.

Once you factor in the cost of a backing plate and buffing pad the price gap between a 7424 and a G100 narrows a bit. Getting the G100 from a Meguiar’s dealer that discounts it narrows the gap a lot. Only you can decide whether the lifetime warranty is worth the final price difference to you. (It is to me.)

Yes, all this is a significant investment. The cost of all of the machines, towels, tools and chemicals I have adds up to much, much less than a single paint job. I consider it a good investment.


PC.