Catalina 34

General Activities => Main Message Board => Topic started by: tommyt on April 05, 2016, 11:41:54 AM

Title: Re-bedding hatches
Post by: tommyt on April 05, 2016, 11:41:54 AM
Both deck hatches have small leaks. Assuming from bedding age. The boat is a 2004.

I have taken off the inside trim to see how the hatches are attached, and was somewhat surprised. I assumed (there I go again making assumptions) that they were through bolted in place when they are just screwed into the deck. Don't want to assume again that this is fairly straight forward project so am asking the board for any details if you have done this project.
I have a couple of roles of MaineSails bedding material that I bought in anticipation of this project.

Questions: What did you use to clean the deck and hatch of old material?
                 Is the bedding material that Mainesail recommends for rebedding  stanchions the right product?
                 Coolest temperature recommended for this project. Want to complete before splash but snowing out.
                 Any helpful hints to do this project correctly the FIRST time?

Thanks for any helpful hints.
Title: Re: Re-bedding hatches
Post by: Ron Hill on April 05, 2016, 11:51:56 AM
Tom : I used 3M4200 to bed in a new center hatch.  It did a great job and I'd recommend it over butyl rubber.  The old hatch was bedded with silicone and cleaned up with lacquer thinner/acetone.

I found the best way to remove the old hatch was to use a heat gun and a stiff putty knife - little by little. 
I wrote a Mainsheet tech article on that subject.

A few thoughts
Title: Re: Re-bedding hatches
Post by: Stu Jackson on April 05, 2016, 12:29:10 PM
4200 is an adhesive, wrong product for the use.  You need a sealant.  Butyl tape from Maine Sail is the right material.

I rebedded our main saloon hatch with it a few years ago.  Ron Hill wrote a Tech Note, February 2012.  I wrote a Tech Note about it in May 2013. 
Title: Re: Re-bedding hatches
Post by: Jon W on April 05, 2016, 01:54:54 PM
Timely topic for me. I was washing down the boat Sunday and notice the trapezoidal hatch leaked. Looking close the gasket is not contacting the frame in the lower port corner. The name on the hatch is BOMAR so I looked up BOMAR for a gasket, but kept getting re-directed to LEWMAR. Is BOMAR or LEWMAR the place to look for a gasket?  Thanks for the help. Jon W.
Title: Re: Re-bedding hatches
Post by: Stu Jackson on April 05, 2016, 04:29:04 PM
Jon,

Two different companies.  Bomar is represented by www.pomanette.com in Florida.
Title: Re: Re-bedding hatches
Post by: KWKloeber on April 05, 2016, 04:31:06 PM
Tom there is an TechWiki artice w/ pics on re doing the old Bowmar 10 x10 hatches.
Butyl is the best material to bed the frame.  I would want to be working with butyl +60F otherwise it's pretty stiff and the frame may bend if not CAREFULLY tightened down a little bit a time.

Ken
Title: Re: Re-bedding hatches
Post by: KWKloeber on April 05, 2016, 04:32:06 PM
Quote from: Stu Jackson on April 05, 2016, 04:29:04 PM
Jon,

Two different companies.  Bomar is represented by www.pomanette.com in Florida.

I got gasket (years ago) for the BM 10x10 from Defender.

kk
Title: Re: Re-bedding hatches
Post by: tommyt on April 06, 2016, 05:26:37 PM
Thanks for the references and advise. Although the hatch on the boat is a Lewmar Low Profile and not a Bomar, they are similar enough for the project. I am just rebedding so will be using all original materials with the exception that I will use Marinesails Butyl tape.

Thanks again.

Tom
Title: Re: Re-bedding hatches
Post by: cmainprize on April 06, 2016, 06:26:57 PM
Tom, every time we pull a fitting that goes through or into the cored deck we drill oversize and fill with thicker epoxy.  Then drill again and replace boot or screw in the sealed deck.  I created a map of the deck so I would remember and over about three years we did them all.  It was over 200 holes
Title: Re: Re-bedding hatches
Post by: Sailing Steve on April 06, 2016, 08:36:38 PM
My $0.02 worth...  I'm a huge believer in butyl tape - inexpensive, doesn't get hard and brittle, easy to clean up/remove, +60F working temp is a huge exaggeration, and much more elasticity than any caulking which equals longevity.

Steve
Title: Re: Re-bedding hatches
Post by: KWKloeber on April 06, 2016, 09:11:18 PM
Quote from: cmainprize on April 06, 2016, 06:26:57 PM
Tom, every time we pull a fitting that goes through or into the cored deck we drill oversize and fill with thicker epoxy.  Then drill again and replace boot or screw in the sealed deck.  I created a map of the deck so I would remember and over about three years we did them all.  It was over 200 holes

If you're not doing it already, the deck fiberglass skin and inside liner skin should remain smaller diameter, and the core removed to a larger diameter.  That provides a lot more strength than just through drilling the whole shebang to a large diameter.  Mainsail shows how (with pics.)

kk
Title: Re: Re-bedding hatches
Post by: tommyt on April 10, 2016, 07:46:33 PM
Where is that Mainesail video? I do not find it on his site.
Title: Re: Re-bedding hatches
Post by: Stu Jackson on April 10, 2016, 08:14:01 PM
Quote from: tommyt on April 10, 2016, 07:46:33 PM
Where is that Mainesail video? I do not find it on his site.

IIRC, it is NOT a video.

http://www.pbase.com/mainecruising/rebedding_hardware (http://www.pbase.com/mainecruising/rebedding_hardware)
Title: Re: Re-bedding hatches
Post by: KWKloeber on April 10, 2016, 08:28:22 PM
Quote from: Stu Jackson on April 10, 2016, 08:14:01 PM
Quote from: tommyt on April 10, 2016, 07:46:33 PM
Where is that Mainesail video? I do not find it on his site.

IIRC, it is NOT a video.

http://www.pbase.com/mainecruising/rebedding_hardware (http://www.pbase.com/mainecruising/rebedding_hardware)

And there's this one on using butyl when replacing portlights....
http://www.pbase.com/mainecruising/nfm_port_lights


kk
Title: Re: Re-bedding hatches
Post by: Stu Jackson on April 11, 2016, 09:00:58 AM
If you are rebedding Beckson ports, use silicone.  It's what they recommend and is the ONLY plae on my boat I'd use it.
Title: Re: Re-bedding hatches
Post by: Ron Hill on April 11, 2016, 02:33:49 PM
Guys : BTW, 3M4200 is listed as an adhesive/sealant and did a great job on my center hatch.

A thought
Title: Re: Re-bedding hatches
Post by: tommyt on April 20, 2016, 02:22:47 PM

Thanks for all the advise on rebedding hatches. The hatches on Escape Hatch are Lewmar Ocean Series and I was very pleased when taking them off to find that Catalina in 2004 was using Butyl Tape to bed them. After removing screws the hatches lifted off easily and the Butyl was still soft and sticky. Took a while to clean off so as to start with a clean surface, but certainly much easier that silicone.

It looks as though someone new to the saw cut the hatch opening over the V-berth. I think they got more than planned and then filled with epoxy to build that section back out. Both top corners had minimal overhang by the hatch. Probably 1/2 inch compared to a full inch on the balance of the edges. Put down a double layer of Mainsials Butyl Tape and dropped the hatch in place. Started loading yesterday, gave the screws another 1/2 turn today, and will wait for warmer weather when tarp is pulled to do final tightening.
In our cool northern weather the boat cover made a great greenhouse to work in, although I am getting a little too old for crawling around all the superstructure.  :D  Now we will wait until in the water to find out just how good a job I did. Right now I am pretty confident it will seal well.