Reply
 
Thread Tools Search this Thread Display Modes
 
Old 04-27-2019, 10:20 AM   #1
Guru
 
JDCAVE's Avatar
 
City: Lions Bay, BC
Country: Canada
Vessel Name: Phoenix Hunter
Vessel Model: Kadey Krogen 42 (1985)
Join Date: Apr 2011
Posts: 2,122
Rough sanding of bottom paint...

What methods and tools are most appropriate for most efficiently prepping your vesselís bottom prior to painting? Do you use a sanding tool or hand sand only? I donít want to remove the existing finish. I only want to get it ready for paint. I assume disposable overalls respirator and hat are appropriate attire.

Jim
__________________
Advertisement

JDCAVE is offline   Reply With Quote
Old 04-27-2019, 10:36 AM   #2
Enigma
 
RT Firefly's Avatar
 
City: Slicker?
Country: Bumpkin?
Join Date: Oct 2007
Posts: 12,184



I would rather work on a dozen clogged heads than do any more bottom work. But that's just me....
__________________

__________________
RTF
RT Firefly is online now   Reply With Quote
Old 04-27-2019, 10:49 AM   #3
Veteran Member
 
Solly's Avatar
 
City: Solomons MD.
Country: USA
Vessel Name: Sun Runner
Vessel Model: 1985 Mainship 34 Trawler MK III
Join Date: Mar 2018
Posts: 96
A lot of Marina's and Boatyards are requiring 'clean' practices on DIY work. Ours even wants a tarp underneath when bottom painting. So..

Random orbit sander with 80 grit paper hooked up to a wet dry vac. Some might say 80 grit is too heavy but I just make a light, skim, pass over the paint to rough it up.
Respirator is a must. As is eye protection. Coveralls, hat and plastic gloves too are nice.
Solly is offline   Reply With Quote
Old 04-27-2019, 11:18 AM   #4
Guru
 
psneeld's Avatar
 
City: Avalon, NJ
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 18,733
Ablative paints usually only require good pressure washing, no sanding.


Other parts at most might just need a quick pass of 80 grit. Any palm sander can do that and be hooked to any sho vac.
psneeld is offline   Reply With Quote
Old 04-27-2019, 12:30 PM   #5
Guru
 
O C Diver's Avatar
 
City: Fort Myers, FL... Summers in Crisfield, MD
Country: USA
Vessel Name: Slow Hand
Vessel Model: Cherubini Independence 45
Join Date: Dec 2010
Posts: 6,823
If you are planning on using Petit Trinidad as we talked about, check the compatibility chart for adhesion over your current paint. Had to have my boat sanded down to the barrier coat. Sean used an orbiting mesh disc sander with the vacuum dust collector.

Ted
__________________
Blog: mvslowhand.com
I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters
O C Diver is offline   Reply With Quote
Old 04-27-2019, 01:45 PM   #6
Guru
 
JDCAVE's Avatar
 
City: Lions Bay, BC
Country: Canada
Vessel Name: Phoenix Hunter
Vessel Model: Kadey Krogen 42 (1985)
Join Date: Apr 2011
Posts: 2,122
Thanks guys. Ted, Iíve decided to use the ďotherĒ lower copper concentration paint from Petit. I just donít want to risk,getting turned back at the border. Its a hard non ablative paint. Itís going onto Trinidad SR. I talked to the people at Trinidad and they said it could go on the Trinidad with only sanding.

So orbital sander, with shop vac attachments. Iíve got all of those. Iím not going to go nuts with it, thatís for sure. And yes to the respirator. Mineís due for replacement. Itís 10 years old now.

Jim
JDCAVE is offline   Reply With Quote
Old 04-27-2019, 01:59 PM   #7
Senior Member
 
City: Great Lakes
Country: USA
Vessel Model: OA 440
Join Date: Aug 2017
Posts: 320
Quote:
Originally Posted by JDCAVE View Post
What methods and tools are most appropriate for most efficiently prepping your vessel’s bottom prior to painting? Do you use a sanding tool or hand sand only? I don’t want to remove the existing finish. I only want to get it ready for paint. I assume disposable overalls respirator and hat are appropriate attire.

Jim
I had the boat hauled during a slack period for the yard, so they had no problem letting it hang in the Travel Lift slings for a few hours. They raised the boat quite high in the slings so I could get under it more easily. A huge concrete block was placed beneath the keel area so that I'd have a chance of surviving if a sling broke. Then I went to work with their power washer. The boat had/has ablative paint, so I kept the nozzle very close to the surface (much closer than normal) and completed a very aggressive wash, which took some pant off along with the bottom crud. Then I used a sheet rock sanding gizmo (sanding pad with a swivel on a pole) and a very aggressive grit scotchbrite type pad to scuff the entire bottom. The scuffing step probably wasn't necessary, but I wanted no issues with adhesion. When I finished sanding/scuffing, I rinsed the bottom and had the boat blocked inside the winter storage building. The actual painting was done the following Spring. Prior to rolling on paint, I brushed off any dust that had accumulated while sitting there over the winter. I used Interlux Micron CSC HS (High Solids) bottom paint. I wore a rubberized painter's suit with hood, and a respirator mask plus goggles during the bottom prep when nasty stuff was dripping all around and onto me. For the roller painting phase I wore a conventional painter's suit. Gloves for both phases. Obviously had plastic down for the paint session. The power wash and scuffing was done over the marina's eco-friendly wash basin, which catches bottom paint residue from all boats during pre-storage bottom wash. The prep phase took about three hours. The paint phase took an afternoon and the following morning (two coats with an overnight cure between them).
Rufus is offline   Reply With Quote
Old 04-27-2019, 02:05 PM   #8
Guru
 
O C Diver's Avatar
 
City: Fort Myers, FL... Summers in Crisfield, MD
Country: USA
Vessel Name: Slow Hand
Vessel Model: Cherubini Independence 45
Join Date: Dec 2010
Posts: 6,823
Quote:
Originally Posted by JDCAVE View Post
So orbital sander, with shop vac attachments. Iíve got all of those. Iím not going to go nuts with it, thatís for sure. And yes to the respirator. Mineís due for replacement. Itís 10 years old now.

Jim
Jim,
If you have a "Shop Vac" brand vacuum, they sell a collection bag that goes inside the tank on the hose connection. This will catch 99% of the paint dust, keep your vacuum from getting messed up by the paint dust, and reduce cleanup to only the vacuum hose. For fine dust collection, they are really slick and fairly inexpensive.

Ted
__________________
Blog: mvslowhand.com
I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters
O C Diver is offline   Reply With Quote
Old 04-27-2019, 02:46 PM   #9
Guru
 
jleonard's Avatar
 
Join Date: Jun 2008
Posts: 3,250
I use a drywall sander, the kind that has a pad attached to a pole.
Then I just "scratch" the bottom to score it.
Saves the back big time.
__________________
Jay Leonard
Attitude Adjustment
40 Albin
Mystic,Ct. /New Port Richey,Fl
jleonard is offline   Reply With Quote
Old 04-27-2019, 03:02 PM   #10
Guru
 
Cigatoo's Avatar
 
City: Narragansett Bay
Country: New England
Vessel Model: Grand Banks 36
Join Date: Sep 2016
Posts: 661
I am having mine glass bead blasted as we speak. Plan is to get clean, barrier coat (2coats), and then a light coat of ablative water based bottom paint. Hopefully as I get older it will just require a pressure wash and a thin coat of ablative every year. If I am going more than a year then 2 coats of ablative.
Cigatoo is offline   Reply With Quote
Old 04-27-2019, 03:54 PM   #11
Guru
 
O C Diver's Avatar
 
City: Fort Myers, FL... Summers in Crisfield, MD
Country: USA
Vessel Name: Slow Hand
Vessel Model: Cherubini Independence 45
Join Date: Dec 2010
Posts: 6,823
Quote:
Originally Posted by Cigatoo View Post
I am having mine glass bead blasted as we speak. Plan is to get clean, barrier coat (2coats), and then a light coat of ablative water based bottom paint. Hopefully as I get older it will just require a pressure wash and a thin coat of ablative every year. If I am going more than a year then 2 coats of ablative.
Have them alternate colors on the barrier coats to ensure complete coverage. Inspect after each coat.

Ted
__________________
Blog: mvslowhand.com
I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters
O C Diver is offline   Reply With Quote
Old 04-27-2019, 03:55 PM   #12
Guru
 
JDCAVE's Avatar
 
City: Lions Bay, BC
Country: Canada
Vessel Name: Phoenix Hunter
Vessel Model: Kadey Krogen 42 (1985)
Join Date: Apr 2011
Posts: 2,122
Rough sanding of bottom paint...

Thanks All. The PO did a full blister peel 6 years ago, just before we bought her. There is 2 coats of Petit Trinidad SR on top of the epoxy barrier coat. The boat has been freshwater moored and has no fouling at all on her. I have pressure washed the bottom and itís free of slime. I have one of those drywall sanding gadgets, and will give it a go with that first. I really donít want to remove too much of the bottom coat. Trinidad is applied with thin coatsóin fact they carefully specify that in the instructions.

Ted: Yup! Already got the bags for the shore vac and all necessary attachments for an orbital sander assuming I go the power tool route. As other have suggested I may try am pole sander. I lent my shop vac to a fellow in the yard several years ago and he left it in mess! I have a second shop vac with an old hose and will use that.

Jim
JDCAVE is offline   Reply With Quote
Old 04-27-2019, 04:03 PM   #13
Guru
 
Comodave's Avatar
 
City: Au Gres, MI
Country: US
Vessel Name: Never Say Never
Vessel Model: President 41 DC
Join Date: Jul 2015
Posts: 3,672
Quote:
Originally Posted by Cigatoo View Post
I am having mine glass bead blasted as we speak. Plan is to get clean, barrier coat (2coats), and then a light coat of ablative water based bottom paint. Hopefully as I get older it will just require a pressure wash and a thin coat of ablative every year. If I am going more than a year then 2 coats of ablative.
What are you using for the barrier coat? 2 coats is probably not adequate for true protection. What does the paint manufacturer recommend as to number of coats? Donít rely on the yard to give you a proper recommendation. Most are willing to cut corners in order to keep it cheaper.
Comodave is online now   Reply With Quote
Old 04-27-2019, 06:29 PM   #14
Guru
 
Cigatoo's Avatar
 
City: Narragansett Bay
Country: New England
Vessel Model: Grand Banks 36
Join Date: Sep 2016
Posts: 661
Quote:
Originally Posted by Comodave View Post
What are you using for the barrier coat? 2 coats is probably not adequate for true protection. What does the paint manufacturer recommend as to number of coats? Donít rely on the yard to give you a proper recommendation. Most are willing to cut corners in order to keep it cheaper.
Frankly I am tempted to skip the barrier coat. Boat has been stored on the hard indoors every winter. If there are no blisters after 34 years I am not sure barrier coat is going to accomplish anything. I thought that I would have them put a couple of coats on so that I can say I did. Alternating gray and white. Thoughts are welcome.
Cigatoo is offline   Reply With Quote
Old 04-27-2019, 06:36 PM   #15
Guru
 
Cigatoo's Avatar
 
City: Narragansett Bay
Country: New England
Vessel Model: Grand Banks 36
Join Date: Sep 2016
Posts: 661
The yard where I store is pretty easy going. I have a guy coming into glass blast the bottom. Friends that own the yard where I dock in the summer will come over and barrier coat. So I guess you could say I am the contractor. Yard is not involved.
Cigatoo is offline   Reply With Quote
Old 04-27-2019, 07:28 PM   #16
Enigma
 
RT Firefly's Avatar
 
City: Slicker?
Country: Bumpkin?
Join Date: Oct 2007
Posts: 12,184
Greetings,
Mr. C. Regarding your anticipated glass blast and barrier coat..."...no blisters after 34 years..."? Why go the bother? If it ain't broke etc.
If anyone can say if there will be any advantage in doing what you propose, I'd love to hear about it.
__________________
RTF
RT Firefly is online now   Reply With Quote
Old 04-27-2019, 07:41 PM   #17
Guru
 
Cigatoo's Avatar
 
City: Narragansett Bay
Country: New England
Vessel Model: Grand Banks 36
Join Date: Sep 2016
Posts: 661
Quote:
Originally Posted by RT Firefly View Post
Greetings,
Mr. C. Regarding your anticipated glass blast and barrier coat..."...no blisters after 34 years..."? Why go the bother? If it ain't broke etc.
If anyone can say if there will be any advantage in doing what you propose, I'd love to hear about it.
I agree. Not sure if barrier coat is necessary on a blister free bottom. Especially if it has 6 months to dry every year. My goal is to eliminate any paint build up so bottom painting will be just a quick coat of water based ablative as I get older. No sanding off old build up every year. In a perfect world the paint would be mostly gone at the end of season.
Cigatoo is offline   Reply With Quote
Old 04-27-2019, 07:53 PM   #18
Enigma
 
RT Firefly's Avatar
 
City: Slicker?
Country: Bumpkin?
Join Date: Oct 2007
Posts: 12,184
Greetings,
Mr. C. I think blasting with glass will require that you barrier coat. Blasting with soda is not supposed to effect your gelcoat BUT will remove any old paint. No experience and anecdotal information only.
__________________
RTF
RT Firefly is online now   Reply With Quote
Old 04-27-2019, 08:00 PM   #19
Guru
 
Cigatoo's Avatar
 
City: Narragansett Bay
Country: New England
Vessel Model: Grand Banks 36
Join Date: Sep 2016
Posts: 661
Quote:
Originally Posted by RT Firefly View Post
Greetings,
Mr. C. I think blasting with glass will require that you barrier coat. Blasting with soda is not supposed to effect your gelcoat BUT will remove any old paint. No experience and anecdotal information only.
We shall see what it looks like tomorrow evening. The blast guy says it is not too abrasive. I think if the Gelcoat is intact and in good shape barrier coat won’t be necessary. However adding a coat or 2 won’t hurt and is a talking point if going to sell.
Cigatoo is offline   Reply With Quote
Old 04-27-2019, 08:14 PM   #20
Enigma
 
RT Firefly's Avatar
 
City: Slicker?
Country: Bumpkin?
Join Date: Oct 2007
Posts: 12,184
Greetings,
Mr. C. "... is a talking point if going to sell." Perhaps but perhaps not. IF there is no obvious advantage in doing so, blasting and barrier coat would raise the spectre of blisters in MY mind. Just sayin'
__________________

__________________
RTF
RT Firefly is online now   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 07:18 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012