Association Forum - Moisture Meters

Assn Members Area · Join

Home.

Association Forum

Ships Store

Cruising

Racing

Technical Tips

Photo Gallery - New

Boat Search - Updated

Manuals & Brochures

Swap Meet

Links

Officer Flag Line & Staff

Bylaws & Constitution

Members Area

Join the Association

Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.

Association Forum

Username:	Password:
Save Password
Forgot your Password?

All Forums

Catalina/Capri 25/250 Sailor's Forums

General Sailing Forum

Moisture Meters

New Topic

Topic Locked

Printer Friendly

Author

Topic

Deric
Captain

Member Avatar

USA
408 Posts

Initially Posted - 01/29/2008 : 19:34:04

Hello Folks,

I was recently made aware that before I paint the bottom of my Cat 25 with a protective coat(s) - - as a preventive measure for potential blistering - - followed by a few coats of antifouling paint, that I should have the boat be checked for moisture.

The use of a moisture meter would be the tool.

My preliminary research on the Internet has resulted in surprised. Apparently, there are those who have the opinion that they are great tools, while others aver these tools should be used a door stops.

I am interested in hearing from others in the association their views on this topic.

Your comments are appreciated.

Thank you,
Deric

Edited by - on

Champipple
Master Marine Consultant

Members Avatar

USA
6855 Posts

Response Posted - 01/29/2008 : 20:02:25

According to the surveyor who did the inspection of my O'day 30 the moisture meter alone isn't enough. A small hammer to tap for dead (but dry) spots should be done and a knowledge of what you are looking for is needed to. There are a number of things that can shoot false positives for water....A wet bilge for one, in some cases areas of solid glass can be another.

You also don't need to strip the bottom in order to take a moisture reading with a meter - it will read through the anti-fouling and the barrier coat without all the sanding. I.E. you can use the meter before you do all the work.

In my opinion, if you are stripping the bottom to bare glass and removing all the blisters you should be okay.

Edited by - on

dmpilc
Master Marine Consultant

Members Avatar

USA
4593 Posts

Response Posted - 01/29/2008 : 21:34:06

If the boat has been in the water for a long time, say several years, let the hull dry out, after sanding, for several weeks, preferrably in the hot summer, before you paint. Yeah, i know that the time out of water is a pain, but it should be worth it.

Edited by - on

Dave5041
Former Mainsheet Editor

Members Avatar

USA
3758 Posts

Response Posted - 01/29/2008 : 22:05:57

Most of what I have read suggests MM's can be useful adjuncts in EXPERIENCED hands. If you have blisters, you have moisture - don't need a meter. If you don't have blisters, you may or may not have significant moisture. Either way the treatment is the same - strip the paint, let the boat dry out for a month or two, fix blisters if ya got'm and barrier coat. I tend to keep things simple and practical.

Edited by - on

stampeder
Master Marine Consultant

Members Avatar

1608 Posts

Response Posted - 01/29/2008 : 22:10:41

Your question begs for more info.

I take it that you already own the boat. If so, and if you already intend on stripping the bottom and doing a proper and complete bottom job - then I would suggest that you strip the bottom down to the gel coat, repair any areas in need of repair with appropriate fiberglass or gel coat repair material (depending on the size of any problems you find under the existing paint - but then thats another question) and then paint on the barrier coat, then the anti-fouling paint.

Regarding the moisture: if you do a proper bottom job, any moisture issues should either dry up and go away, or indicate that another area of the boat needs to be attended to.
Your boat should not have water in the bilge. If you have no indication of moisture or moisture related problems, you probably don't have to measure anything.
I did a bottom job two years ago on my 25 year old C25. There were a few little blisters that I fixed up and painted over. After two years, my boat's bottom looks very good. I had this boat surveyed when I bought it four years ago - the surveyor tapped the boat with a little hammer and said it was solid as the day it was built. He did not use a moisture meter.
What boat do you have, where is it and how long ago was it in the water. Hope this helps - ask more questions, it keeps me out of the kitchen

Edited by - on

Champipple
Master Marine Consultant

Members Avatar

USA
6855 Posts

Response Posted - 01/29/2008 : 22:15:23

Oh and Welcome!

Edited by - on

Dave Bristle
Master Marine Consultant

Members Avatar

Djibouti
10005 Posts

Response Posted - 01/30/2008 : 09:11:48

IMVHO... Moisture is particularly an issue in a cored hull. Catalina hulls are not cored. The meter is important for checking the deck (as part of a survey), but short of having blisters or grounding damage, you are unlikely to have moisure problems in the hull laminate.

The next issue is what is the meter telling you... My experience with a professional surveyor is that its signals should be interpreted by a pro--they may mean trouble, or they may mean "put this on your to-do list, but not necessarily at the top." As noted, a ball hammer is used in conjunction with the meter to help figure out what's going on. Check for blisters, put on a barrier coat (more important in fresh water), and paint away.

Edited by - on

Deric
Captain

Members Avatar

USA
408 Posts

Response Posted - 01/30/2008 : 18:32:50

Hello Folks,

Very helpful and interesting information within this thread. I particulary became interested in this subject because for the past two months of research regarding bottom painting and anti-fouling paint, no one had mentioned a moisture meter until I spoke with an engineer at Yachtpaint (Interlux).

Afterwards, I wanted to learn more regarding the subject. Hence, one site I found interesting:
http://www.yachtsurvey.com/moisture_meters.htm

Nonetheless, my '78 Cat 25 hull is in good shape. No evidence of blistering. Because the boat has been out of the water since October, I suspect that a good sanding, barrier paint followed by several coats of anti-fouling, should be good.

I was advised that 4-5 coats of barrier (Interprotect 2000) and three coats of Micron33 would be good for fresh water lake.

One notion is favorable, a meter in the hands of someone who knows boats, and who has experience reading MM, in addition to other observable conditions, is much better able to determine the status of a boat's condition, than a DIY without experience.

Thank you all for you comments.
- Deric

Edited by - on

Dave Bristle
Master Marine Consultant

Members Avatar

Djibouti
10005 Posts

Response Posted - 01/30/2008 : 20:41:19

Good article. I was gratified by what they said about Coremat, which is employed in my new hull (as one of its eight laminations). To my knowledge, Catalina does not use "chopper guns", so given that their hulls are also not cored, you should be good to go.

Welcome to the group, and stick around!

Edited by - on

Topic

New Topic

Topic Locked

Printer Friendly

Jump To:

Association Forum

Notice: The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.