Pneumatic -vs- Electronic DA sanders?

[rkm]

I'm about to begin a gelcoat restore on my boat. I'm not a professional detailer, simply an avid car/boat enthusiast who likes to keep his stuff shiney.

I was looking through AutoGeek to determine the best products for restoring gelcoat and I noticed that Mike used the Griot's DA unit.

I have a pneumatic DA 6", which I'm familiar with, and had planned to use that, until I arrived here and noticed that not many people use pneumatics.

I wondered if there is a reason all of you more experienced people use the electronic over the pneumatic? Does anyone have some sort of objective comparison between the pneumatic and electronic DA orbital sander/polishers?

Thank you in advance,
RKM

[tag4car]

Most likely the air consumption, and the smallest compressor to run an air d.a draws 15amps. However air machines do usually weigh less than electric

[C. Charles Hahn]

http://www.autogeekonline.net/forum/...ish-paint.html

[PorscheGuy997]

I wondered if there is a reason all of you more experienced people use the electronic over the pneumatic? Does anyone have some sort of objective comparison between the pneumatic and electronic DA orbital sander/polishers?

There are a number of reasons why air tools are not commonly used on enthusiast detailing forums.

First, some do not have the space required for a big air compressor. Second, a comparable air setup can really be expensive. Third, many users do not work on enough vehicles to warrant a large setup.

Even though I have a compressor big enough to run an air DA without the compressor running constantly, I mainly use electric polishers. They are not necessarily quieter, but I don't have to hear the air compressor fire up occasionally. Not to mention the fact that dragging an air compressor to a customers' house is not easy.

Air polishers can be close in specifications to an electric DA, but I don't see them taking over...

[rkm]

Thank you for the comments (and the link to the related post).

I realize now, that I've only used my DA in a on/off environment, rather than consistently. Although the CFM requirement of most pneumatic sanders is enough to be servied by a mid-size 15amp compressor, it would be a pain if the compressor had to run non-stop. In my experience, that's not a great thing.

At least it's good to know that the difference in the hardware itself, is not significant, and that I can use either in a pinch.

Thanks again for the great info!

[Mike Phillips]

I'm about to begin a gel coat restore on my boat. I'm not a professional detailer, simply an avid car/boat enthusiast who likes to keep his stuff shiney.

Hi RKM,

We completely understand the part about keeping things shiny... when I first bought the 1967 Starline Deville in the pictures and links below the gel-coat was pretty much white over all the horizontal surfaces. To say the gel-coat was oxidized would be a very strong understatement.

For fun... and even sport... I used a variety of products "systems" to undo the damage and restore a showroom new finish. It required the power of a rotary buffer to cut off all the dead, oxidized gel-coat. I'm pretty confident from the extreme oxidation on the boat, and the fact that I was the second owner of the boat, that the original owner for 42 years never heard of the words "Boat Wax", let alone anything related to the words regular maintenance.

Anyway, here's one before shot that shows the entire horizontal surfaces were chalky white except where I restored just a section.




Here's after the initial buff-out... sans chrome trim...



This was after putting the chrome trim back on...




Here's some pictures I took July 4th weekend...






This was taken at Manatee Cove boat launch after a day at the Stuart Sandbar... (busy and crowded)




And here's the thread that shows the process...

1967 Starline Deville - Extreme Makeover


I don't know what condition your hull is in but if you have a lot of oxidation I would recommend getting a rotary buffer with a 100% Twisted Wool Aggressive Cutting Pad and an aggressive compound to cut off all the dead, oxidized gel-coat.

[sabrina]

Well, gel-coat was pretty much white over all the horizontal surfaces.

[rkm]

Hi Mike,
Thanks a million for taking the time to reply.

By the way, off-topic, I'm down here in Palm Beach County, and I always wondered if you have a storefront there, or whether AutoGeek.net is virtual-only?

In my original post, I was referring to the 1967 Starline Deville post you quoted above. I was making plans based specifically around your advice in that post, and a later post where you referred to it.

What I took away from it was, essentially (summarized):

Of the 3 tests you did, the most recommended was the 3M approach. Essentially that was:

1) 3M Marine Rubbing Compound 09004 -- 3x Times
Heavy Wool Cutting Pad (twisted wool)
Approx 1600 RPM on DA Orbital

2) 3M Marine Finesse-It II Glaze 09048 -- 1x Time
CCCS Orange (or) Hydro-Tech Tangerine Pads
Approx 1600 RPM on DA Orbital

3) 3M Marine Liquid Wax 09026 -- 1x Time
Meguiar's W8006 6.5-Inch Soft Buff Pad
Approx 1900 RPM on DA Orbital

I'm sure I've interpreted some of that incorrectly. Thank you in advance for any corrections/clarifications you might be able to offer :-)!

[Mike Phillips]

Of the 3 tests you did, the most recommended was the 3M approach. Essentially that was:

1) 3M Marine Rubbing Compound 09004 -- 3x Times
Heavy Wool Cutting Pad (twisted wool)
Approx 1600 RPM on DA Orbital

2) 3M Marine Finesse-It II Glaze 09048 -- 1x Time
CCCS Orange (or) Hydro-Tech Tangerine Pads
Approx 1600 RPM on DA Orbital

3) 3M Marine Liquid Wax 09026 -- 1x Time
Meguiar's W8006 6.5-Inch Soft Buff Pad
Approx 1900 RPM on DA Orbital

I'm sure I've interpreted some of that incorrectly. Thank you in advance for any corrections/clarifications you might be able to offer :-)!

That will work.

The key to your results will be the first step and that's cutting off the dead, oxidized gel-coat. For this you basically want a liquid sandpaper and apply it with a wool cutting pad with a rotary buffer.


The 3M Marine Rubbing Compound is very aggressive and should work for most projects that are severely neglected.


About 3 weeks ago I re-compounded the hood and the spot on the back of the boat that was never restored but left to show before and after differences. For his work I used the Gel Coat Labs Heavy Cut Compound with a wool pad on a rotary buffer and it cut fast too...

Gel Coat Labs Heavy Cut Compound, fiberglass compound, boat compound polish


Either the 3M or the Gel Coat Labs product will work for you. I'm kind of a system approach guy, that is if I'm going to use 3M, then I'll try to use the 3M system so each product builds off the results of the previous product and there's a chemical synergistic compatibility because in most cases the chemist that creates the first step product, since he knows what's in the first product knows better how to formulate all the follow-up products.

Some guys will mix and match all the way through any buffing project I call this,

Freestyling

That is starting with 3M, then using Meguiar's, then follow with Collinite, etc.

The non=system approach can work too...

[rkm]

Hi Mike,
Thank you for the reply and clarification.

Regarding the first coat being the most important .. I have oxidation that appear to be much worse than the initial photos of your Deville. Worse yet, I have some fairly deep scratches that are probably 1/3 of the way through the gel coat.

For this reason, I had planned on wet-sanding everything prior to compounding. I didn't mention it above because I was replying specifically to your original post, however, my plan included a Pre-#1 process:

a) Apply some gelcoat fixes to scratched, blistered areas. Use a thickening product like West Marine, in the gelcoat, for the areas that require some "build" to them.

b) Sand the gelcoat fixes with 240, 320, 500, 600, 800, 1000 -- then start the 1,2,3 compound process mentioned above.

c) Sand the other areas of the boat with 600, 800, 1000 -- then start the 1,2,3 compound process mentioned above.

For the wet-sanding, I was considering something like the net-style Mirka wet-sanding paper.

Do you feel that this sequence (P240 through P1000 ... then 3M Super Duty Compound) is a natural progression that will not be too abrupt between any of the steps?

PS - You did not mention, can I buy directly at your location, next time I'm up that way?

Thank you in advance!
-RKM