Water entering into the space between the outer and inner halves of the deck causes rotting of the balsa-wood core, and that in turn weakens the deck structure so that small cracks appear in the gelcoat, looking like a hard-boiled eggshell that has been dropped. How does one fix such a thing economically? I wonder if a THINNED solution of acetone and 105/206 epoxy, injected under pressure through a series of small holes drilled through the top layer of the deck in the effected area would set up inside of the rotted wood fibres and thereby restore most of the stiffness of the structure by solidifying in the rotted balsa-wood core? Has anyone attempted this type of a fix? How well did it work? (I have read of a repair of this type using unthinned epoxy, after removal of the rotted wood, but thought that this method would be quite difficult, and only suitable for a smaller area of damage, so I am looking for any easier way. Is there any such a thing? )
Balsa Core-dry rot solution question
- Thread starter Skippercanuck
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reference book
I was looking past posts on deck rotting and several people recommended looking at Don Casey's book "Inspecting an Aging Sailboat" as a place to start.
I was looking past posts on deck rotting and several people recommended looking at Don Casey's book "Inspecting an Aging Sailboat" as a place to start.
Balsa core rot
I'm not sure if you have an easy or inexpensive solution. I had a C-Scow with bad balsa core material. It had turn into a liquid over time (well, sort of liquid) I wound up cutting out the inside hull material, cleaming out the goo and replacing it with cedar waffers. I then burried everything in epoxy and re-glassed the inside of the hull. It worked very well but was a real pain to do. Using epoxy in large volume is tricky as it get too hot and can distort or melt the hull if you use too much at one time. Years ago, I almost found out the hard way with a customer's boat. Fortunately, I had a hose near by.
I'm not sure if you have an easy or inexpensive solution. I had a C-Scow with bad balsa core material. It had turn into a liquid over time (well, sort of liquid) I wound up cutting out the inside hull material, cleaming out the goo and replacing it with cedar waffers. I then burried everything in epoxy and re-glassed the inside of the hull. It worked very well but was a real pain to do. Using epoxy in large volume is tricky as it get too hot and can distort or melt the hull if you use too much at one time. Years ago, I almost found out the hard way with a customer's boat. Fortunately, I had a hose near by.
Thinning Epoxy
You can thin West Sytem epoxy, but not without consequences. There is a very nice treatment of the subject here: http://www.westsystem.com/ewmag/14/ThinningEpoxy.html I have affected extensive repair to damaged balsa core, covering most of the different techniques. If you are not going to replace the core material I would suggest using a ready-made penetrating epoxy product like Git-Rot. In any case, the amount of penetration you can expect is dependent on how dry you can get the core material. So, it would be advisable to drill many small holes in the area and dry the core either by: leaving it out in the warm dry air for many days, using a hair dryer (not too hot as it can cause delamination in non-damaged areas), pouring acetone in which will take the water with it as it evaporates, or a combination of these methods. Also, how are you planning on applying pressure to inject the epoxy? I'm no expert, but the Gudgeon Bros (West System) are, so read their info. Good luck!
You can thin West Sytem epoxy, but not without consequences. There is a very nice treatment of the subject here: http://www.westsystem.com/ewmag/14/ThinningEpoxy.html I have affected extensive repair to damaged balsa core, covering most of the different techniques. If you are not going to replace the core material I would suggest using a ready-made penetrating epoxy product like Git-Rot. In any case, the amount of penetration you can expect is dependent on how dry you can get the core material. So, it would be advisable to drill many small holes in the area and dry the core either by: leaving it out in the warm dry air for many days, using a hair dryer (not too hot as it can cause delamination in non-damaged areas), pouring acetone in which will take the water with it as it evaporates, or a combination of these methods. Also, how are you planning on applying pressure to inject the epoxy? I'm no expert, but the Gudgeon Bros (West System) are, so read their info. Good luck!
Oday 23 balsa core replacement
I replaced the balsa core on a section of my deck about three years ago. I have a 1974 O'day 23 that started to feel soft just forward of the mast step. I used a cutting wheel to cut through the outer skin from just aft of the mast step and around the front hatch. I then peeled back the skin, removed the soggy core material, glassed in a new balsa core between the inner skin and the outer skin that I had peeled away and repaired the cut with new glass. I then went through the extremely difficult process of sanding and painted the entire deck and cockpit with Awlgrip. The job took me several months, but the deck is now like new. I looked at other methods to repair the core, but realized that the core had turned to mush, and even if I could dry it, and inject material in, the voids that would be unavoidable (no pun intended) would create problems in the future. I've had this boat for 27 years and plan to keep it another 27 so I felt it was worth it to do the job right.
I replaced the balsa core on a section of my deck about three years ago. I have a 1974 O'day 23 that started to feel soft just forward of the mast step. I used a cutting wheel to cut through the outer skin from just aft of the mast step and around the front hatch. I then peeled back the skin, removed the soggy core material, glassed in a new balsa core between the inner skin and the outer skin that I had peeled away and repaired the cut with new glass. I then went through the extremely difficult process of sanding and painted the entire deck and cockpit with Awlgrip. The job took me several months, but the deck is now like new. I looked at other methods to repair the core, but realized that the core had turned to mush, and even if I could dry it, and inject material in, the voids that would be unavoidable (no pun intended) would create problems in the future. I've had this boat for 27 years and plan to keep it another 27 so I felt it was worth it to do the job right.
New Product for core rot fix!
Following up on my earlier post, I have found a 2-part epoxy that is made to stick to wet/damp core balsa that is called "Gluvit". The dealer is PRO hardware "dykemans" in St John, NB. No website, phone 506 634 1852 (ask for Reg). He says that you just drill a number of holes, clean out with a drill/bent nail in the usual way and then inject the stuff with a syringe or caulking gun, wait for it to set up, sand, and then overcoat the hole with gelcoat tinted to match. The stuff cost about $50.00(cdn) per quart. Too easy, no waiting for the core to dry out. He says its a sure fix and no "Gitrot" is needed, as the Gluvit is a low-viscosity penetrant that sets up as a solid. Anybody ever heard of this fix?
Following up on my earlier post, I have found a 2-part epoxy that is made to stick to wet/damp core balsa that is called "Gluvit". The dealer is PRO hardware "dykemans" in St John, NB. No website, phone 506 634 1852 (ask for Reg). He says that you just drill a number of holes, clean out with a drill/bent nail in the usual way and then inject the stuff with a syringe or caulking gun, wait for it to set up, sand, and then overcoat the hole with gelcoat tinted to match. The stuff cost about $50.00(cdn) per quart. Too easy, no waiting for the core to dry out. He says its a sure fix and no "Gitrot" is needed, as the Gluvit is a low-viscosity penetrant that sets up as a solid. Anybody ever heard of this fix?
Balsa Core problems
I had a soft spot in the deck and after looking at several possible solutions, cut out the bottom layer of fiberglass from inside the hull. I thought that the spot was small, but had to do a lot of cutting before I found dry wood and ended up with a section about 5' long x 12" wide along the forward port side. I used a Dremel Tool with a fibreglass reinforced cutting wheel to cut the glass. This was easy (after removing the liner - not so easy). Peeling off the fiberglass was not easy except where the balsa was rotten and the pieces of fiberglass I cut out could not be reused. When I thought that I had reached dry wood, I cut out a piece of core but still found that when I squeezed the wood, water would appear. I doubt that you will get all the water out by drilling holes. Balsa can hold a lot of water and because the wood is installed with the grain perpendicular, water is trapped. I ended up, working upside down, installed new balsa and fibreglass, but feel that the job is OK. After installing the liner, the repairs can not bee seen. About 30 to 40 hours of work over several weeks (weather was too cold thru April).
I had a soft spot in the deck and after looking at several possible solutions, cut out the bottom layer of fiberglass from inside the hull. I thought that the spot was small, but had to do a lot of cutting before I found dry wood and ended up with a section about 5' long x 12" wide along the forward port side. I used a Dremel Tool with a fibreglass reinforced cutting wheel to cut the glass. This was easy (after removing the liner - not so easy). Peeling off the fiberglass was not easy except where the balsa was rotten and the pieces of fiberglass I cut out could not be reused. When I thought that I had reached dry wood, I cut out a piece of core but still found that when I squeezed the wood, water would appear. I doubt that you will get all the water out by drilling holes. Balsa can hold a lot of water and because the wood is installed with the grain perpendicular, water is trapped. I ended up, working upside down, installed new balsa and fibreglass, but feel that the job is OK. After installing the liner, the repairs can not bee seen. About 30 to 40 hours of work over several weeks (weather was too cold thru April).
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