Did my porter cable 7424 break?
- Thread starter svtcobra
- Start date
Stokdgs
dansautodetailing.com
Did the backing on the pad separate from the pad ?
Is the backing on the backing plate clean so that pads will stick to it really well ??
Dan F
Yup the backing plate broke off. Just ordered a new one. The pad was clean no issues there.
First time using speed 6 and this happened.
Accumulator
Well-known member
svtcobra- I`m still confused about just what broke...the plate, its stud, what? I gather it wasn`t some part of the PC itself that broke.
While I ran my PC at 6 a lot, many here would say that`s too high. Remember that the PC7424 isn`t really meant to be used as a polisher with a foam pad loaded with product; it`s intended to run a (lightweight) backing plate holding as single sheet of sandpaper.
What size was that pad? I could never get anything done via PC unless I used a pad no larger than 4", and 3" was better. (BUT then again...the only time I`ve ever done real damage with a polisher was running a 4" pad on a PC, and I was using a mild pad/product combo too!
)
While I ran my PC at 6 a lot, many here would say that`s too high. Remember that the PC7424 isn`t really meant to be used as a polisher with a foam pad loaded with product; it`s intended to run a (lightweight) backing plate holding as single sheet of sandpaper.
What size was that pad? I could never get anything done via PC unless I used a pad no larger than 4", and 3" was better. (BUT then again...the only time I`ve ever done real damage with a polisher was running a 4" pad on a PC, and I was using a mild pad/product combo too!
)
Stokdgs
dansautodetailing.com
I have used Porter Cable`s 7424 for over 2 decades, changed the counterweight to enable use of the 5" backing plate, ran it always on speed- 6, and never had a backing plate fail..
Now, I don`t use it for paint correction ever because it will take years longer than my Makita, but it has always been used for easier things like all the glass, moonroof glass, etc..
So you are saying that the hard plastic backing plate that the pad velcro`s to, broke?? In half?? What size was it ? Did you change out the counterweight if it was the 5" backing plate first ?
FYI, because there is so much vibration, jiggling, etc., on this machine and perhaps all others, I never turn the speed all the way up with the machine facing up or down,- in the air-.. It has to be on the panel, etc., with some downward pressure on it.. Think about all that extra stuff hanging off the -end- that was never designed to be there..
Dan F
svtcobra- I`m still confused about just what broke...the plate, its stud, what? I gather it wasn`t some part of the PC itself that broke.
While I ran my PC at 6 a lot, many here would say that`s too high. Remember that the PC7424 isn`t really meant to be used as a polisher with a foam pad loaded with product; it`s intended to run a (lightweight) backing plate holding as single sheet of sandpaper.
What size was that pad? I could never get anything done via PC unless I used a pad no larger than 4", and 3" was better. (BUT then again...the only time I`ve ever done real damage with a polisher was running a 4" pad on a PC, and I was using a mild pad/product combo too!
So what are you using for polishing? For me its been the PC for 98%
Accumulator
Well-known member
I basically...don`t. I haven`t had to correct anything except a few RIDS for many years. Eh, I`m not a Pro and only do our vehicles, which seldom get marred.
But when I need to, I use the Flex 3401 for aggressive work, Cyclos or GG6 or GG 3" pneumatic or BOSS15 or Rupes Mini for the other stuff. But again, they really just sit on the shelf. Haven`t reall used the Rupes or BOSS15 enough to even have an opinion of `em, thought the BOSS15 does seem to cut quicker than the others.
Accumulator
Well-known member
Did you notice a significant diff between the counterweights? I put the 5" one on at least one of my PCs (don`t really remember) since I always use small pads, but didn`t *really* notice much difference.
The weight diffs between the (oe) PC plates is pretty negligable, so counterweight diffs made to accommodate that never struck me as really applying to pads wet with product, which weigh *so much more* (somebody here did a comparison and it was really something).
Lucky guy to have so many toys. I do remember when the Cyclos was a big topic here.
svtcobra- I`m still confused about just what broke...the plate, its stud, what? I gather it wasn`t some part of the PC itself that broke.
While I ran my PC at 6 a lot, many here would say that`s too high. Remember that the PC7424 isn`t really meant to be used as a polisher with a foam pad loaded with product; it`s intended to run a (lightweight) backing plate holding as single sheet of sandpaper.
What size was that pad? I could never get anything done via PC unless I used a pad no larger than 4", and 3" was better. (BUT then again...the only time I`ve ever done real damage with a polisher was running a 4" pad on a PC, and I was using a mild pad/product combo too!
sorry for my late reply I didn`t get an email notification like I used to I thought no one responded on my thread.
I used 5" pads for years now on the machine.
I`m not sure how to describe what broke but does look like the stud.
do you know what standard size backing plate comes with the Porter-Cable from the factory?
I don`t think I changed anything with the counterweight for the past 10 years or so since I`ve owned the machine I just used it whatever way it came. The stud is fine its the backing plate that disintegrated. I ordered a 5-inch backing plate from Amazon and it fits inside but the size of the plate is much smaller than the original.
Menzerna medium cut polish step 2(500)
Yeah the backing plates gets worn in the end. So sometimes a switch to a new can be a safe thing to do before any oops happens. As soon as notice that the pads comes off easier than before when you switch them it`s time for a new backing plate. Look once and a while around the bolt and also where the metall plate is attached to the backing plate. If you change backing plates often between different sizes. Switch to a new plastic washer that`s between the backing plate and the polisher. You can buy a bunch of the extra plastic washers on Autopia and AGO and don`t cost much. It saves the backing plate and also you from vibrations.
Accumulator
Well-known member
"Yes indeed!" on being lucky.
I *still* love those Cyclos, only polishers I can actually *enjoy* using. Build like things used to be too...decades of use barely breaks `em in.
svtcobra said:
So glad to hear the stud isn`t broken off in its threaded hole!
Which plate was oe depends on which model you got- 7336 or 7424 (IIRC, those #s are from memory...from the `90s). The *ONLY* diffs between the two models are 1) which size plate and 2) which (matching) counterweight. I bought one of each, and/but I`ve switched my plates/weights so many times I can`t remember which unit is which.
PC has offered different styles of plates in the two sizes over the years, but it`s interesting that your new 5" one is smaller than what you originally had. Huh..that`s got me stumped!
All worked out well in the end. My old pads were larger than my new 5" backing plate but the job was completed. Whew.
Accumulator
Well-known member
Ah, glad to hear that! All`s well that ends well
