SailNet Community banner
41 - 60 of 60 Posts

· Wish I never found SN!
Joined
·
2,123 Posts
Reaction score
304
Call me stupid if I have missed something. How bad is this rotted/wet core? Could you possibly use the West System and saturated the area with epoxy pumped in under pressure. At my marina in Queensland there is a CT 41 that has had this procedure done and and it turned out very good and solid.
 

· Not just a member
Joined
·
111 Posts
Reaction score
11
Call me stupid if I have missed something. How bad is this rotted/wet core? Could you possibly use the West System and saturated the area with epoxy pumped in under pressure. At my marina in Queensland there is a CT 41 that has had this procedure done and and it turned out very good and solid.
I have done many repairs of this type. Pumping epoxy in is not the best repair. It is a good stop gap measure until a complete and proper repair can be made. There are several issues that need to be dealt with such as: Killing all of the rot spores present (if balsa or plywood)to prevent the rot from spreading, complete drying before injection, not causing more delamination by using too much pressure in an attempt to completely fill any voids., increased weight, and decreased strength.
 

· Registered
Joined
·
504 Posts
Reaction score
12
Simon - unless you're dealing with a very small area (less than 1 sq ft) then "drilling and filling" is completely inadequate. I tried it when I was intimidated by the prospect of cutting open the decks and doing a proper recore.

What I found is that a recore, in addition to being the right way of repairing it, is also far easier.

I would not use the drill and fill for a stop-gap; it makes the eventual recore much more difficult as you have to get all of that cured epoxy out of there. That's no fun and causes unnecessary damage to the remaining skin.
 

· Registered
Joined
·
5 Posts
Reaction score
0
Don't and try and reinvent the wheel. Coring is fixed from the outside. Cut out bad core, and leave inner laminate in place and rebuild on that laminate. Or hire a professional to do the job properly.
 

· Super Moderator
Joined
·
6,859 Posts
Reaction score
2,832
While..

While you can drill & fill DRY deck delamination, as can happen in foam cores or in hot environments, you can not effectively fix wet core with this method. Wet core is wet core no matter how much epoxy you inject in. Epoxy only penetrates dry rot. If the core is moist the epoxy will not displace the water and take its place. In 25 years of tearing into boats I've yet to see a cored deck or cored lamination that exhibited dry rot. It's always either wet or dry but I've never seen dry rot..

Penetrating epoxies, or thinned West System, is meant for dry not wet core fixes. Even then it does not work very well and does not penetrate as one may think it would..
 

· Registered
Joined
·
5,979 Posts
Reaction score
714
Heck Trevor just cut the top off, take it home and make a new one with the fittings you need where you need them, then tab and glass it back on and non-skid the whole thing.
Custom boat with a solid deck to walk on, lighter than the original.
 

· Telstar 28
Joined
·
43,281 Posts
Reaction score
297
LOL... while this sounds simpler, you'd have to make the fiberglass far heavier than the cored deck would be to get the same strength and stiffness. :)

Heck Trevor just cut the top off, take it home and make a new one with the fittings you need where you need them, then tab and glass it back on and non-skid the whole thing.
Custom boat with a solid deck to walk on, lighter than the original.
 

· Read Only
Joined
·
87,689 Posts
Reaction score
825
Well - you sound like you and your posse are ready to take on a big project so I'll wish you well. A couple of suggestions...

Don't pull the entire underside ot the deck off at one time. The boat will flex and you'll be epoxying a few bends and twists into the hull that shouldn't be there. Do it a small section at a time.

Think about using an alternate method. Cut 2 1/2 inch longitudinal channels out of the existing underside. Lay in a 3/4" stringer (wood/foam/carbon fibre/whatever) and then cover the stringer with several layers of roving. Once you have a complete structure of stringers, finish it off with some trnasverese ribbing done the same way. Then core between the stringers - use Airex. Cover everything with a bit of roving.

Remember NOT to use balsa in areas where hardware will pierce the deck. It is not strong enough from a compression standpoint. Use plywood. Make epoxy plugs on each hole.

Good Luck - Post Pics !!
 

· I don't discuss my member
Joined
·
2,557 Posts
Reaction score
190
Discussion Starter · #53 ·
I plan to document this repair the best I can to help others considering it's a pretty common problem. I got my bags packed for the weekend, going sailing saturday, and dropping the mast when we get her back in the slip. Also going to clean her out, and ready for the start on Feb 8th.

Sailormann, thanks for the tips!
 

· Telstar 28
Joined
·
43,281 Posts
Reaction score
297
Well - you sound like you and your posse are ready to take on a big project so I'll wish you well. A couple of suggestions...

Don't pull the entire underside ot the deck off at one time. The boat will flex and you'll be epoxying a few bends and twists into the hull that shouldn't be there. Do it a small section at a time.
This is very good advice.

Think about using an alternate method. Cut 2 1/2 inch longitudinal channels out of the existing underside. Lay in a 3/4" stringer (wood/foam/carbon fibre/whatever) and then cover the stringer with several layers of roving. Once you have a complete structure of stringers, finish it off with some trnasverese ribbing done the same way. Then core between the stringers - use Airex. Cover everything with a bit of roving.
This is more work, but probably a better choice in the long run.

Remember NOT to use balsa in areas where hardware will pierce the deck. It is not strong enough from a compression standpoint. Use plywood. Make epoxy plugs on each hole.
Make the sections where the hardware comes through the deck solid glass that is tapered to meet the cored areas so you don't get a hard transition line if you can avoid it. Solid glass is a much better solution than pads of plywood, since the plywood can rot.
 

· I don't discuss my member
Joined
·
2,557 Posts
Reaction score
190
Discussion Starter · #56 ·
One last question on materials, I'm looking at picking up the following and wanted to know what else I was missing. Please feel free to chime in.


750361
Epoxy Resin 105-B 10.3 Lbs. $68.99 $68.99
This item is on sale. - Our Regular Price: $74.99 - You are saving: $6.00

--------------------------------------------------------------------------------

750364
Fast Hardener 205-B 2.3 Lbs. $30.99 $30.99

--------------------------------------------------------------------------------

750408
Colloidal Silica 406-7 0.8 Lbs. $17.99 $17.99

--------------------------------------------------------------------------------

751507
Episize 9oz. Glass Tape 733 4.4 Lbs. $90.99 $90.99

--------------------------------------------------------------------------------

Subtotal: $208.96
 

· Registered
Joined
·
35 Posts
Reaction score
1
what else?

Buy the dispenser pumps for the epoxy--well worth the cost. Also, I have always thought West episize fiberglass was overpriced, its much cheaper to buy a few feet off of a roll and to cut your own strips. Just make sure the cloth (esp. mat or cloth/mat composites) are compatible with epoxy. Last time I think I bought cloth from raka, but there are numerous sources if you search for them.
 

· Registered
Joined
·
695 Posts
Reaction score
16
I have done this on fairly small sections, no more than maybe a foot square. I used wax paper over 1/4" plywood propped up with flexible wooden pieces to first hold the coring in place then the two layers of glass. I will be doing 4 more small spots as soon as it is warm enough.

Worked fine, no real issues but I would be nervous about a large area. Start small and see how it goes.

Good Luck
Gary
 

· I don't discuss my member
Joined
·
2,557 Posts
Reaction score
190
Discussion Starter · #60 ·
I have two peices in place now. I do have photos but won't be able to upload them until tomorrow. I'll be down this weekend to continue the work. I may only repair about a foot in front of the chain plates this season, and complete the work next winter. We'll see how this weekend goes.
 
41 - 60 of 60 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top