Bottom paint over Gel Coat without Barrier Coat? - SailNet Community
 1Likes
Reply
 
LinkBack Thread Tools
post #1 of 18 Old 04-23-2008 Thread Starter
Junior Member
 
Join Date: Apr 2008
Posts: 14
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
Bottom paint over Gel Coat without Barrier Coat?

Hi all,

Here's a question which I'm sure may have been asked before: I spent last weekend trying to strip the old layers of bottom paint & barrier coat off my sailboat's 28' hull. What a job! I got to about 1/3 of the hull with a hook scraper when mu arms, shoulders & back ran out of strength. Some parts went right down to the gel coat where others went down to the barrier coat. My thinking is to sand everything smooth with an orbital sander, apply a few layers of anti-foul (no barrier coat) and put her in the (salt) water for the season. The gel coat, at least where I scraped down to it, appears to be sound. The intention would be to redo the hull in the fall when she's on the hard again. Would a season in the water have any detrimental effect on the gel coat if I do it this way?

Thanks,

John
WagTheDog is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #2 of 18 Old 04-23-2008
ASA and PSIA Instructor
 
Join Date: Apr 2000
Posts: 3,566
Thanks: 7
Thanked 24 Times in 24 Posts
Rep Power: 16
 
I would say no, unless there is any evidence that the barrier coat is there as a result of a blister repair. If so, the blister problem may well return, and repairing new blisters later would be more trouble than restoring the barrier coat now. You should be able to tell whether there was a blister problem by inspecting those areas of gelcoat you can see - if they don't have patched divots you should not need to worry.

PS - don't remove any of the existing barrier coat if you can avoid it, you are jsut creating work for yourself to restore it.

Certified...in several regards...
sailingfool is online now  
Quote Quick Reply Share with Facebook
post #3 of 18 Old 04-23-2008
Senior Member
 
Join Date: May 2002
Posts: 2,691
Thanks: 6
Thanked 31 Times in 29 Posts
Rep Power: 14
 
I just finished that job last year, and you're going to love the results, in case you have any doubts.

I would paint it with the barrier coat now, rather than putting on antifouling and doing it next season. Stripping it is by far the hardest part, and, if you put on antifouling this year, you'll have to strip it again next year. It doesn't take that long to roll on the barrier coats, and then roll on the antifouling, and then you're done! It made me a little late to launch last year, but I got my sailing in by crewing for other folks. I'm just starting boat prep this year, and it'll be a snap.
Sailormon6 is offline  
Quote Quick Reply Share with Facebook
post #4 of 18 Old 04-23-2008 Thread Starter
Junior Member
 
Join Date: Apr 2008
Posts: 14
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
Thanks for the responses!

J
WagTheDog is offline  
Quote Quick Reply Share with Facebook
post #5 of 18 Old 04-24-2008
Member
 
lbdavis's Avatar
 
Join Date: Apr 2007
Location: Portland, ME
Posts: 560
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
 
If Wag was going to put a barrier coat on, wouldn't he need to remove all the existing bottom paint first? I have been under the impression that barrier coat could not be applied on top of anti-fouling paint.
lbdavis is offline  
Quote Quick Reply Share with Facebook
post #6 of 18 Old 04-24-2008
Member
 
TThomsen's Avatar
 
Join Date: Oct 2007
Location: Alberta
Posts: 52
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 8
 
I'm curious. Could you sandblast the the bottom and the put on the barrier coat ?
TThomsen is offline  
Quote Quick Reply Share with Facebook
post #7 of 18 Old 04-24-2008
Member
 
lbdavis's Avatar
 
Join Date: Apr 2007
Location: Portland, ME
Posts: 560
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
 
Sandblasting can be a dangerous proposition as it can easily tear into the fiberglass lay-up quite easily and create more problems than it solves. Look into soda-blasting if you're looking for quick ways to strip. I have no personal experience with it, but I hear good things.
lbdavis is offline  
Quote Quick Reply Share with Facebook
post #8 of 18 Old 04-24-2008 Thread Starter
Junior Member
 
Join Date: Apr 2008
Posts: 14
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
I heard that sandblasting was a practice followed not too long ago but the more effective method these days is soda blasting - literally blasting the hull at high pressure with coarse baking soda. The cost seems to be around $40/ ft and the results are guaranteed. I spoke to a guy that told me that it would take a day for my 28' and that the hull would be stripped down to the gel coat by the time he was done.

J
WagTheDog is offline  
Quote Quick Reply Share with Facebook
post #9 of 18 Old 04-24-2008
Senior Member
 
T37Chef's Avatar
 
Join Date: Oct 2006
Location: Maryland
Posts: 4,489
Thanks: 74
Thanked 42 Times in 37 Posts
Rep Power: 9
 
Soda blasting is the preferred method these days, easier on the gel coat. I think waiting till the fall will do little or no harm to your boat, especially if you see little or no signs of blistering.

Yes, you must remove all the old bottom paints before applying a barrier coat. After having mine blasted I sanded it done smooth and removed any remaining bits of old paint.

Cheers,
Shawn

S/V Windgeist
1982 Tartan 37C

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
T37Chef is offline  
Quote Quick Reply Share with Facebook
post #10 of 18 Old 04-24-2008
Senior Member
 
Join Date: May 2002
Posts: 2,691
Thanks: 6
Thanked 31 Times in 29 Posts
Rep Power: 14
 
Maybe I'm mistaken, but I thought you said you either scraped or sanded off all the antifouling, and that the only thing remaining is some of the barrier coat, which you are going to sand smooth at the edges. If so, I think you can apply barrier coat over it all, and then apply your antifouling. If all the antifouling is gone, you don't need to do any sand or soda blasting.

On a previous boat, I removed all antifouling from the keel, and left some of the old barrier coat, and added new barrier coat over the old, and it worked fine.
Sailormon6 is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Barrier Coat & Antifouling paint shipley Gear & Maintenance 7 08-09-2009 09:18 AM
Paint Build-up or Barrier Coat? cas8100 Gear & Maintenance 29 05-09-2008 11:25 AM
The Bottom Paint Blues Don Casey Gear and Maintenance Articles 0 06-22-2003 08:00 PM
bottom paint barrier coat rbh1515 Gear & Maintenance 2 02-25-2001 03:52 PM
Paint the Bottom Yourself Tom Wood Gear and Maintenance Articles 0 03-09-1999 07:00 PM

Posting Rules  
You may post new threads
You may 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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome