| Re: wet sanding question
[Re: Jalani]
#93123 12/22/06 04:59 AM 12/22/06 04:59 AM |
Joined: May 2006 Posts: 954 Mumbles Y.C Wales U.K Mark P
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Posts: 954 Mumbles Y.C Wales U.K | Yellow and black striped hulls, must have been bees wax <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" /> MP*MULTIHULLS | | | Re: wet sanding question
[Re: Jalani]
#93124 12/22/06 05:54 AM 12/22/06 05:54 AM |
Joined: Feb 2004 Posts: 3,528 Looking for a Job, I got credi... scooby_simon Hull Flying, Snow Sliding.... |
Hull Flying, Snow Sliding....
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Posts: 3,528 Looking for a Job, I got credi... | When I've repaired GRP in the past I've always gone 400/600/800/1200 and finished off with G6 cutting compound (fine). For dark colours you sometimes need to follow up with G10. Then buffed with a good quality wax. The results are invariably as good as new. Hey, John, that looks like an old Condor !
F16 - GBR 553 - SOLD I also talk sport here | | | Re: wet sanding question
[Re: scooby_simon]
#93125 12/22/06 06:56 AM 12/22/06 06:56 AM |
Joined: Feb 2005 Posts: 1,382 Essex, UK Jalani
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Posts: 1,382 Essex, UK | Hey, John, that looks like an old Condor ! At the time (1978) it was quite a NEW Condor! <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" /> So what was the giveaway? - The 'Condor 1978' sticker on the transom? <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" /> I think it was about 2-3 years old, we'd had a bit of an accident with it and ripped a big chunk out of the stbd hull bottom. The reason for the photo was that I was rather chuffed with the finished repair. Using Jake's 8'/ 5'/ 2' repair standard, it was about a 2" standard of repair! <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" /> | | | Re: wet sanding question
[Re: catman]
#93126 12/22/06 07:36 AM 12/22/06 07:36 AM |
Joined: Jun 2001 Posts: 12,310 South Carolina Jake
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Posts: 12,310 South Carolina | 600 grit will buff fine. Anymore than 1000 is wasting your time.
Use an aggressive compound first then an Glazing compound to finish. I've had trouble getting a 600 grit finished followed buffing to sustain a shine longer than a month or so with the Team Seacats blue N20. I'm going to go up a level with the sanding and try buffing again.
Jake Kohl | | | Re: wet sanding question
[Re: papayamon2]
#93133 12/22/06 09:35 PM 12/22/06 09:35 PM |
Joined: Jun 2001 Posts: 12,310 South Carolina Jake
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Posts: 12,310 South Carolina | to do real polishing, like catman says, it should look like a side angle grinder but with a rubber head, pad, and wool cover. If you were to leave this one running over one place too long, it will do damage. Should look like this (I've never seen one with a random orbit) A random orbiting buffer (the kind that you find in the automotive section at walmart that mostly vibrates) will do a good job applying wax, but it will not work with rubbing compounds very well at all.
Jake Kohl | | | Re: wet sanding question
[Re: papayamon2]
#93135 12/23/06 08:12 AM 12/23/06 08:12 AM |
Joined: Jun 2002 Posts: 1,658 Florida Suncoast, Dunedin Caus... catman
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Pooh-Bah
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Posts: 1,658 Florida Suncoast, Dunedin Caus... | I have a Dewalt 849 var. speed. Got it from a local auto paint supply, $100. Use a wool bonnet with the aggressive compound and a foam bonnet with the glazing compound.
Since your local, if you haven't already, you should go down to Fiberglass Coatings in St. Pete. They're on 19 just before 38th ave on left. They have everything you would ever need and are very helpful.
Have Fun
| | | Re: wet sanding question
[Re: catman]
#93136 12/23/06 08:59 AM 12/23/06 08:59 AM |
Joined: Apr 2002 Posts: 695 Ft. Pierce, Fl. USA Seeker
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Posts: 695 Ft. Pierce, Fl. USA | The best pads for the polishers are one piece...they thread right on to the standard 5/8" shaft of the polisher (which all serious polishers share)...they don't have strap on bonnets or rubber backing pads...they are about $18.00-$20.00
Here is what the manufactures rep for "Buff Magic" wrote me...
Our Buff Magic is used extensively by many boat manufacturers for polishing sanded gelcoat for repairs during the production process. All gelcoat sprayed after the fact of being pulled from the mold is sanded, and orange peel is unavoidable, so if yours is slight, you are to be commended on your application skills. Buffing from 400 is not recommended, nor is it a common grit to start buffing from. Most manufacturers buff at a minimum of P600 or finer. And for large areas such as an entire hull, you will highly benefit from going finer, such as P800 or P1000. The time and effort in sanding to a finer grit will save buffing time tenfold compared to the extra time sanding. Using only 400 grit will leave too coarse of scratches requiring much more buffing time and effort, and also will require multiple applications to remove all of the scratches. Multiple applications in addition to being time consuming will degrade the gelcoat beyond what is necessary, and also generates a lot more "heat" which can shrink the gelcoat, and create irregularities, and can cause a "print through effect" of the fiberglass behind the gelcoat. Additionally it is much easier to produce gloss when buffing finer scratches such as P800 or P1000. Buff Magic will work effectively from P600 and finer, but for your application to large areas, P800 or P1000 is recommended.
Jason Brennan OEM Account Representative | | | Re: wet sanding question
[Re: papayamon2]
#93138 12/31/06 07:58 AM 12/31/06 07:58 AM |
Joined: Jun 2001 Posts: 12,310 South Carolina Jake
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Posts: 12,310 South Carolina | If the polishing job was effective, the shine will hold up well over time. If it wasn't terribly effective, the shine you are seeing is probably more the waxes, oils, and/or fillers that are in the rubbing compound. This is what I'm experiencing with the Team Seacats N20 and why the shine isn't holding up (since I stopped at 600 grit before buffing)
I've had really good results with NuFinish liquid wax - or any of the modern waxes that have UV inhibitors in them. My F18 gets at least two coats a year and it is holding up very well.
Jake Kohl | | |
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