MacGregorSailors.com

hamshog wrote:Paul, I am looking at the West Marine catalog and there is a 3M product #m restorer and wax page 474. Is this the product you used?

Don't have the catalog in front of me..but here it is WM#149395

Fiberglass Restorer & Wax - Pint

Stuff is expensive...but works well. It works 110% better with a DA polisher than by hand. You can try it by hand..but the results will not be that dramatic ....will be good..but won't take it to the next level. I used it by hand once ...then went back to the machine.

Paul

Paul

Thanks for the info. That is the one that I was looking at. It is called 3M restorer & wax. I also have a polisher.

Lowe's Depot has a 10" polisher @ 3/4 amp. and a 6" @ 1/2 amp.
Question is, the 10" looks like a better deal, but is the added .25 amp of power significant in boat polishing, and more critically, is 10" diameter polisher going to be harder to use than the six, on tight curves, around hardware, and ? tight places ? on the Mac. ??
Also, was considering using my two cabin batteries (series 24) to power my 125-Watt inverter so i could polish out the black oxid. around the windows, while in my slip (no shore power there). Would the half-amp version run significantly longer on the 2 batteries ??

Finessit (sp?) by 3M is a good way to get swirl marks out and remove chalkiness. Follow up with 3M cleaner wax, then Colonite if you want it to really shine.

Lets see..

Power (Energy per unit time) is found by Volts times Amps , giving units of Watts

Those amperages refer to 120 VAC operation so you can figure:

10 inch will consume roughly 120 VAC * 3/4 equals 90 Watts of power

6 inch will consume roughly 120 VAC * 1/2 equals 60 Watts power

Each group 24 battery I estimate as good for 1 kWatt hour of use, so the 10 inch should run 10 hours per battery, and the 6 inch 16 hours per battery

You shouldnt run the batteries down more than 1/2 of course, but either battery looks like it should do a 3-4 hour polishing job easily, on a single group 24 battery

I believe inverters run at near 90-100% efficiency, unless you get a really bad one,...Ive left that factor out of the above.

how about the comparative usability on the Mac's hull surfaces, re. the 6" vs. the 10" polisher ?? Is the 10 inch at a disadvantage from difficult accessibility on small areas of the deck ? Or is the added size a significant advantage on large areas. ?

I've been told these small buffers such as are available form Home Depot, WalMart et al don't have the HP, both literally and figuratively, to handle a job the size of the Mac.

I've had one for two seasons, but I've not been willing to take the time to do the whole boat, so I can't really say. I actually have two of them (long story), so if I ever decide to take the time and one dies, I'll be able to keep going.

Since the Mac is about 90% large flat surfaces, I'm not too concerned about the 10" model not being suitable for tight curves and smaller broken up areas on the topsides.

However, since area varies by the square of diameter, the 10" polisher is nearly three times larger than the 6", but with only 50% more power. So in power per unit area, the smaller unit is actually better by a significant margin.

Chip... great analysis....
right on... almost 3 times the area for 10 vs. 6-inch....

if Pi is taken as 3.1415
Pi x r squared = area of circle

6" dia. ..... 3" squared =9 , 9x Pi = 28.27 sq.in.

10" dia. ..... 5" squared = 25, 25x Pi = 78.53 sq.in.

so the smaller one at 60 watts would run better (more powerfully) and longer, which you would need - more time - to do the job at less area covered per minute.
Maybe.....

Paul, your boat looks awesome! Makes me wish I got the blue hull instead.

delevi wrote:Paul, your boat looks awesome! Makes me wish I got the blue hull instead.

Yea..it looks great for about a day or so.. Macgregor's gelcoat seems super sensitive and scratches with the slightest touch...

I mean...I should have never needed heavy duty rubbing compound on a brand new hull. Even after using it ...the scratches were (still) visible, but significantly reduced... Most people wouldn't see/notice them..but I do..

The blue does make the boat look far more expensive than it really is..

Paul

ALX357...NICE MATH ...who said Mac owners are stupid... but I cant find a formula or equation to calculate the difference between a blue and white hull speed...yet.
white hull.