[obpsti2006]

I have read alot about folks using the Porter Cable orbital buffer/sanders with great success. I own a 7336 from Lowes and retrofit it with a 3M "Hook It" 6" Backing Plate and 10" "Perfect It" polishing pad. My counter-weight is OEM equipped for the 6" Plates. The device came equipped with a 6" backing plate for attachment of adhesive backed sanding discs so I know all the items are corresponding. Here's my dilema...

When I buff horizontally with the Porter-Cable (ie; the hood, trunk or roof of my STi) the buffer spins and orbits flawlessly at any speed. Even when applying mild pressure to the surface. When the buffer is placed into a vertical position (ie; buffing the doors and fenders) the damn thing just vibrates at high speed. The pad will, at the lightest application of pressure, almost stop and just vibrate on the surface of the panel. Upon release of any mild pressure the RPMs will ramp up and wildly sling polish everywhere. I have found that to buff vertically I have to crank it up to 5500-6k RPM. At that point the pad's rotational speed increases but my hand physically goes numb from the vibrations. Its unusable. What am I doing wrong? What could be wrong?
If its a 3M incompatibility, please have realistic information about it. Not just because "system X" is what someone pushes on the Forums here.

Sincere thanks in advance to those who respond.

-J

[TurboMoe]

My guess is it's the 10" pad. I don't think the PC has enough power to turn a 10" pad effectively enough to do paint correction. Like it's putting too much load on it, that would explain how it almost stops with just a little pressure on vertical panels. Biggest pads I've used on my PC are 5.5", heck the biggest I have for my Flex is 6.5".

Just my two pennies worth, I'm sure someone else will chime in.

[vetteboi88]

I'd say it was the oversized pad myself. I couldn't be certain as I've only used 6" pads on my PC. I've never heard of useing a 10" pad on a 6" backing plate either.

[Rennes]

If you want to use a 10", you have to switch out your counter-balance part on the portercable.

[obpsti2006]

So would triming the circumfernce of the pad to a 6" margin be acceptable? Sadly 3m doesn't sell 6" pads (so I am told). I am not against converting to a 5" system if you really think it would help. Shame to cut that expensive pad up, but if it doesn't work, its useless anyways. I'll try it and report back.

[upncummr]

Here's a link to Griot's Garage. Griot's Garage 6" Random Orbital - Griot's Garage

At the bottom of the page there are links to various pads that work with the 6" base. Maybe these are what you're looking for.

Gary

[obpsti2006]

Trimmed the pad to 6" and it did improve the performance somewhat. I still have to ramp the speed to about 5k to get consistant vertical pad movement. That was definately an issue. The hand numbing vibrations are gone. Thanks for the input so far. If others have success with something or have experienced this problem and found a "ultimate solution" please continue to post up! Thanks everyone!! -J

[TurboMoe]

When you say 5k, you mean you roll the switch to 5? I always take mine up to 6 when polishing. If you were trying to do it on a lower speed then that's also a contributing factor to your problem with it stopping. PC plus a 10" pad probably takes a long time to break down polish, add a low speed to that and it would take forever.

If the hand numbing-ness is gone with the trimmed down pad that's probably as good as you're going to get. I didn't notice how much vibration there was with the PC until I started using my Flex. Still use my PC for small places and really bad scratch spot correction though.

[obpsti2006]

Yeah i was afraid of the speed would "burn" something. After playing with it the last day now with the smaller pad I am not sure a Porter Cable could unless you were trying. Whats the "FLEX" I keep hearing everyone mention? Could you give me a link?

[TurboMoe]

I have the Flex 3401 Orbital, Flex also makes a rotary. The Flex is bigger, has more power. Makes doing correction ten times easier (for me at least). For me I wanted something that worked quicker then the PC but I don't feel comfortable enough to go straight rotary.

I think you'd really have to put effort into it to burn through the clear with a PC.