Grinder / sander recommendation? - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance
 Not a Member? 
  #1  
Old 09-21-2009
cghubbell's Avatar
1977 CS27 ~ Ravat
 
Join Date: May 2009
Location: Ontario, NY (PYC)
Posts: 157
Thanks: 4
Thanked 0 Times in 0 Posts
Rep Power: 6
cghubbell is on a distinguished road
Question Grinder / sander recommendation?

Well, I just finished watching my first haul out. The boat is on the cradle, and I had my first look at her hull. Yep, she's got blisters. With my month-early haul-out I have a perfect opportunity to get the blisters ground out and drying. Only problem is, what to use?

I have a nice (Porter Cable) random orbit sander, and a traditional (Makita) square plate palm sander. I even have a Dremel... However, I'm thinking that working a 27' hull-o-blisters probably warrants something that will work faster, right?

Can anyone recommend criteria / features to look for (rpm speeds? sizes? amps? Something else?). I can go down to Lowe's and roll the dice, but I'm hoping someone can give me something to go on. If you have one that you really like, and you think it was reasonably priced, please let me know

I was looking at a "PORTER-CABLE 4-1/2" 7.5-Amp Angle Grinder", but it looks like these have stone wheels... Don't I want to be using sandpaper discs? Do I have the totally wrong tool here?

Thanks,
Chris
__________________
CS27 #1254 ~ Ravat
PYC, Lake Ontario

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #2  
Old 09-21-2009
Capnblu's Avatar
Senior Member
 
Join Date: Mar 2006
Location: Squamish
Posts: 659
Thanks: 0
Thanked 4 Times in 4 Posts
Rep Power: 9
Capnblu is on a distinguished road
Well Chris, I have just completed grinding all of the bad paint and gel-coat off of a 42 Tayana. I used Makita products. I used the mid sized makita grinder, It had plenty of power, and wasn't such a brute as a full size large grinder. For the sanding I use either a 5" random orbit variable speed for finishing, or the 5" regular random orbit for the bulk or coarser grits. The real magic is in the abrasives you will use. Regular sandpaper loads up, and doesn't cut very well, however some very ingenious individual came up with a sanding disk that is called a flap wheel. Mounted to your angle grinder, it is capable of removing anything, and I mean ANYTHING, with EASE! they are available in grits from 36, up to 120. These discs, even at 120 grit, could go through the most tenacious material, and show little signs of wear. They cost about $10 each, but the beauty is that you will probably only need 1. I used 2, I stripped off a total deck of cracked and crazed gelcoat, and the entire topsides of 2 part polyurethane, and primer. They are by far the best thing I have used on my rebuild. I will get you the MFG. name tomorrow. I have seen a similar product by WALTER ABRASIVES, but have not yet used one of theirs, because the ones I have won't wear out! One thing to keep in mind, is if you decide to grind the old away, do it with HORIZONTAL STROKES. that way when you go to trowel on your epoxy, you will have an easier time re-fairing it. Don't do it haphazardly.
__________________
Why, why, why?
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

I Don't Know! I Don't Know!
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #3  
Old 09-22-2009
ezatsea's Avatar
I can't reMember
 
Join Date: Sep 2009
Location: where the moment takes me
Posts: 16
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
ezatsea is on a distinguished road
Chris,
I like Milwaukee tools myself, but they're really all about the same. Any 4 1/2 inch grinder with those flap discs capnblu mentioned is a pretty good weapon of choice. The bigger the grit the better, I'd start with 36. You may want to check with where you're hauled out, some places require you to attach a vacuum to any sander or grinder to prevent any antifouling on the bottom from getting into the environment (that's how it is where I'm hauled out in CA). I bought a Festool sander for this purpose and attached it to my shopvac with a length of bilge hose. The sander was pricey but one of the best tools I've owned. Have fun!
__________________
Ed
s/v casa chica
S&S Swan 43

Keep the boat IN the water,
keep the water OUT of the boat.
Reply With Quote Share with Facebook
  #4  
Old 09-22-2009
cghubbell's Avatar
1977 CS27 ~ Ravat
 
Join Date: May 2009
Location: Ontario, NY (PYC)
Posts: 157
Thanks: 4
Thanked 0 Times in 0 Posts
Rep Power: 6
cghubbell is on a distinguished road
Yes, we need to put a tarp on the ground when we sand, and I think use of a vacuum is a good idea regardless of the rules, so I'd planned on it. That was one of the criteria I'm interested in - how well does the dust port on various models really collect dirt. Being a woodworker I've seen all kinds of variety in how well they work on other tools.
__________________
CS27 #1254 ~ Ravat
PYC, Lake Ontario

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #5  
Old 09-22-2009
maccauley123's Avatar
SailAway
 
Join Date: Sep 2004
Location: Biddeford, ME
Posts: 162
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 10
maccauley123 is on a distinguished road
I use a 4" right angle grinder for jobs like that, really good at taking material off quickly.
__________________
You will regret the things you did not do, more than the things you did.

Get out there!

Saco Bay, Maine
1971 Ericson 29
Reply With Quote Share with Facebook
  #6  
Old 09-22-2009
T37Chef's Avatar
Senior Member
 
Join Date: Oct 2006
Location: Maryland
Posts: 4,043
Thanks: 51
Thanked 25 Times in 24 Posts
Rep Power: 8
T37Chef will become famous soon enough
We are in a "Certified Clean Marina", I rented this from the marina when I did my bottom sanding job.

Combined with their vacuum attachment for fine particles, I found it ideal and not too heavy. After many many hours of sanding my arms still felt like there were going to fall off

Random Orbital Sanders - Festool

and
__________________
Shawn
Tartan 37 - S/V Windgeist

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Photo by Joe McCary
Reply With Quote Share with Facebook
  #7  
Old 09-22-2009
cghubbell's Avatar
1977 CS27 ~ Ravat
 
Join Date: May 2009
Location: Ontario, NY (PYC)
Posts: 157
Thanks: 4
Thanked 0 Times in 0 Posts
Rep Power: 6
cghubbell is on a distinguished road
As a follow up question, is an angle grinder interchangeable with a random orbit sander for blister removal? Or do I really want to use the angle grinder for initial blister removal, then the random orbit for when I'm fairing the repaired hull?

I see the use of "sander" and "grinder" mixed somewhat inconsistently in how-to articles, so it's hard to tell just what I need...

Thanks,
Chris
__________________
CS27 #1254 ~ Ravat
PYC, Lake Ontario

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #8  
Old 09-22-2009
Senior Member
 
Join Date: Jul 2008
Location: chesapeake bay
Posts: 1,942
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 7
scottyt is on a distinguished road
the angle grinder is the tool of choice, the random orbit is good for paint and fairing but way too slow for real removal of material.

another option for blister opening is a sand blaster in very talented hands, or even a soda blaster but its slower.
Reply With Quote Share with Facebook
  #9  
Old 09-22-2009
cormeum's Avatar
48' wood S&S yawl
 
Join Date: Aug 2009
Posts: 421
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 5
cormeum is on a distinguished road
Quote:
Originally Posted by T37Chef View Post
We are in a "Certified Clean Marina", I rented this from the marina when I did my bottom sanding job.

Combined with their vacuum attachment for fine particles, I found it ideal and not too heavy. After many many hours of sanding my arms still felt like there were going to fall off

Random Orbital Sanders - Festool
I do a lot of sanding every year- Love my Festool.
It won't be as aggressive as aright angle grinder if you're grinding out blisters. But my 150 with a heavy grit takes down epoxy REALLY fast.
Reply With Quote Share with Facebook
  #10  
Old 09-22-2009
Sabreman's Avatar
Senior Member
 
Join Date: Sep 2006
Location: Yeocomico River, VA
Posts: 1,571
Thanks: 2
Thanked 14 Times in 11 Posts
Rep Power: 9
Sabreman will become famous soon enough Sabreman will become famous soon enough
I just finished the job using a 6" random orbit Rigid sander. Worked great and was aggressive enough to get the job done without going through the hull. On our last boat, I used an angle grinder and will never do it again. The high RPM (22,000) is too much for fiberglass, IMHO. On the other hand, the 6" random orbit sander is quite aggressive, much more than a 5" grinder. The increase of only 1" diameter yields 44% more grinding area.

The Rigid had a silly dust bag that I took off. The good news is that it easily accepts the hose of a Shop Vac. I did the entire hull with the Rigid/ShopVac setup and had great results using 40/60/120 grit. You don't need to press hard.

To get all the paint off, you may not want to grind. We used 1" wood chisels to scrape it off, sharpening frequently. We also used carbide-tipped paint scrapers. When the paint was removed, I used the sander to smooth everything out. MUCH faster than sanding through many layers of paint. Also, the chisels/scraper gave us paint chips vs. paint dust. MUCH easier to collect!

Once I got to bare glass, I used an ice pick to gouge out the few blisters that I had. I would not grind since you will end up going too deep. I also recommend popping the blisters in the fall and filling them with epoxy in the spring. You'll need the winter for them to dry out.

Good luck.
__________________
Sabre 38 "Victoria"
Reply With Quote Share with Facebook
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Living without refrigeration book recommendation erps General Discussion (sailing related) 6 09-18-2006 09:30 AM
recommendation for racing/cruising sails mcagney Racing 9 05-01-2006 07:20 AM
Boat Buying Recommendation bluerider32 Boat Review and Purchase Forum 2 12-19-2005 10:03 AM
Grinder as Sander? CJV Gear & Maintenance 4 05-19-2005 03:00 AM
Literature Recommendation for Beginner Cruiser in Puerto Ric Colinkites2000 Cruising & Liveaboard Forum 1 04-05-2004 09:40 PM


All times are GMT -4. The time now is 04:07 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.