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Fishwisher’s core rot removal

 
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Teufelshunde



Joined: 27 Aug 2019
Posts: 117
City/Region: Sebastopol
State or Province: CA
C-Dory Year: 1987
C-Dory Model: 22 Angler
Vessel Name: Fish Wisher
Photos: Fishwisher
PostPosted: Mon May 18, 2020 8:20 pm    Post subject: Fishwisher’s core rot removal Reply with quote

I didn’t want to hijack Jackie’s thread so I started my own - seems like there is a lot of us fixing rotten balsa as of late!
I posted pictures in my album today as to what I have found so far under my port side fuel tank and plan on exploring the starboard side tomorrow and will probably find the other half of the detour (see pictures and you’ll get it) it’s amazing what some people think is a good idea!
I was surprised to find that my core is 1-1/2 thick I thought it would be 3/4. My question is - does anyone know where I could source the core replacement and also what grade of end grain balsa?
I am planning on replacing with balsa unless there is a better recommendation? I need to be able to over drill and epoxy the holes to secure the tank when repairs are completed.
Any thoughts, ideas or comments appreciated,
Fish on!

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Barry Rietz



Joined: 21 Jun 2006
Posts: 267
City/Region: Sierra Vista
State or Province: AZ
PostPosted: Mon May 18, 2020 10:06 pm    Post subject: Rotten to the Core Reply with quote

Teufel, Nice job on both the boarding ladder install, and the rot repair found in the forward hatch area. Apparently at the time of the build, the factory used two layers of 3/4" end grain balsa as shown in your photos. Once you have assessed the starboard side I would obtain a moisture meter and check the balsa that remains and "appears" to be free of moisture. If there is no moisture observed, I would nevertheless dry this area using heat lamps before going forward. If it were my project, I would source "Airex" or "Kledgacell" closed cell rigid foam in the highest density available and use epoxy to secure the patch. The "foam" will never absorb water and will provide a nice base on which to add the final "glassmat" laminate, again using epoxy resin.
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Jackie



Joined: 18 Oct 2015
Posts: 78
City/Region: Ketchikan
State or Province: AK
C-Dory Year: 2008
C-Dory Model: 16 Cruiser
Vessel Name: Lil' Bit
Photos: Lil Bit
PostPosted: Mon May 18, 2020 11:28 pm    Post subject: Reply with quote

Teufelshunde, I so feel your pain. At least you found the edges - everytime I cut further I uncover a big area of water. Soon I'll have everything removed!

I also have a 1.5 inch core and found that a product called CoreLite comes in thicknesses up to 4 inches. I haven't priced it. It's in Miami and shipping to Alaska probably won't be cheap. If you find anything closer, let me know. I'll also keep looking.

Your user name made me wonder if you were in the Marines?
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thataway



Joined: 02 Nov 2003
Posts: 17792
City/Region: Pensacola
State or Province: FL
C-Dory Year: 2007
C-Dory Model: 25 Cruiser
Vessel Name: thataway
Photos: Thataway
PostPosted: Tue May 19, 2020 6:10 pm    Post subject: Reply with quote

I wonder how many of the boats had 1 1/2" thick cores? You can make balsa as thick as.you want. My very close friend's 55 foot boat was entirely Built of balsa planks, fiberglass inside and out. He made 3 circumnavigations--no problems. Also hit a mostly submerged container (at the corner) at 8 knots when racing off Mexico--no water intrusion and we sailed several hundred miles back "Home"...

You are going to have to have some kerfs to get the flexibility to follow the hull contour. Ideally all of the kerfs should be filled with resin. Usually one side has a layer of mat on it to hold the scrim together. If laying up with polyester resin, you will put a layer of mat on top before the 1708.. If epoxy, then probably a layer of thin cloth, or mat designed for epoxy on the top and saturate the core with the epoxy. Epoxy is stronger and better adhesion with secondary bond. But it is considerably more expensive. Doing in essence the whole boat polyester makes more sense.

You can either use the 1 1/2" thick material. and only a few places carry bales core more than 3/4" thick. Or you can use two layers of the 3/4", with light mat between, saturated with resin.

When you lay the balsa on the inside of the boat cutter skin, you will want to trowel on resin thickened with cabosil to fill any voids on the inside of the floor. Use a notched trowel as you would laying ceramic tile.

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Teufelshunde



Joined: 27 Aug 2019
Posts: 117
City/Region: Sebastopol
State or Province: CA
C-Dory Year: 1987
C-Dory Model: 22 Angler
Vessel Name: Fish Wisher
Photos: Fishwisher
PostPosted: Wed May 20, 2020 10:45 pm    Post subject: Reply with quote

Jackie wrote:
Teufelshunde, I so feel your pain. At least you found the edges - everytime I cut further I uncover a big area of water. Soon I'll have everything removed!

I also have a 1.5 inch core and found that a product called CoreLite comes in thicknesses up to 4 inches. I haven't priced it. It's in Miami and shipping to Alaska probably won't be cheap. If you find anything closer, let me know. I'll also keep looking.

Your user name made me wonder if you were in the Marines?


Jackie,
I found a place in Colorado that can do 1-1/2 Balsa and am expecting a response in a few days for a price (I think it’s pretty pricey but we’ll see).
Yes I was in the U.S. Marines from 94-2001 as a Longshoreman and a “PMI” (marksmanship instructor).
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Teufelshunde



Joined: 27 Aug 2019
Posts: 117
City/Region: Sebastopol
State or Province: CA
C-Dory Year: 1987
C-Dory Model: 22 Angler
Vessel Name: Fish Wisher
Photos: Fishwisher
PostPosted: Wed May 20, 2020 11:04 pm    Post subject: Reply with quote

thataway wrote:
I wonder how many of the boats had 1 1/2" thick cores? You can make balsa as thick as.you want. My very close friend's 55 foot boat was entirely Built of balsa planks, fiberglass inside and out. He made 3 circumnavigations--no problems. Also hit a mostly submerged container (at the corner) at 8 knots when racing off Mexico--no water intrusion and we sailed several hundred miles back "Home"...

You are going to have to have some kerfs to get the flexibility to follow the hull contour. Ideally all of the kerfs should be filled with resin. Usually one side has a layer of mat on it to hold the scrim together. If laying up with polyester resin, you will put a layer of mat on top before the 1708.. If epoxy, then probably a layer of thin cloth, or mat designed for epoxy on the top and saturate the core with the epoxy. Epoxy is stronger and better adhesion with secondary bond. But it is considerably more expensive. Doing in essence the whole boat polyester makes more sense.

You can either use the 1 1/2" thick material. and only a few places carry bales core more than 3/4" thick. Or you can use two layers of the 3/4", with light mat between, saturated with resin.

When you lay the balsa on the inside of the boat cutter skin, you will want to trowel on resin thickened with cabosil to fill any voids on the inside of the floor. Use a notched trowel as you would laying ceramic tile.


Bob,
It sure didn’t seem that the balsa I removed had any type of separation or resin filled kerfs (if my understanding is correct as to kerfs) under the fuel tanks.
There is a very slight curve from outside edges to center of boat aft. but I plan on saturating the new core in un-thickened epoxy for sure.
I have been reading the west systems epoxy manual and watching their you tube tutorials which are helpful - it also has been a better understanding for me as I used to do body and paint work for a few body shops in the late 80’s into the early 90’s but little fiberglass work,I appreciate your knowledge thank you.
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Teufelshunde



Joined: 27 Aug 2019
Posts: 117
City/Region: Sebastopol
State or Province: CA
C-Dory Year: 1987
C-Dory Model: 22 Angler
Vessel Name: Fish Wisher
Photos: Fishwisher
PostPosted: Wed May 20, 2020 11:14 pm    Post subject: Re: Rotten to the Core Reply with quote

Barry Rietz wrote:
Teufel, Nice job on both the boarding ladder install, and the rot repair found in the forward hatch area. Apparently at the time of the build, the factory used two layers of 3/4" end grain balsa as shown in your photos. Once you have assessed the starboard side I would obtain a moisture meter and check the balsa that remains and "appears" to be free of moisture. If there is no moisture observed, I would nevertheless dry this area using heat lamps before going forward. If it were my project, I would source "Airex" or "Kledgacell" closed cell rigid foam in the highest density available and use epoxy to secure the patch. The "foam" will never absorb water and will provide a nice base on which to add the final "glassmat" laminate, again using epoxy resin.


Thanks Barry I’m currently researching and appreciate your thoughts - I definitely cut back far enough to hard core material and it’s been in the 70’s here so I’m letting it sit in the sun for the next few days to make sure everything is bone dry.
If the balsa is too pricey I’m going to look into the “foams” further.
Thanks again.
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Marco Flamingo



Joined: 09 Jul 2015
Posts: 949
City/Region: Seattle
State or Province: WA
C-Dory Year: 2004
C-Dory Model: 16 Cruiser
Vessel Name: Limpet
Photos: Limpet
PostPosted: Thu May 21, 2020 9:10 am    Post subject: Reply with quote

As I recall, I looked around and C-Dory in Bremerton was the easiest and quickest supplier (for me). Although I found it cheaper elsewhere, the time/money of of shipping a 2x4" piece of 3/4" balsa was crazy (the box would weigh more than the contents). I took a leisurely drive to Bremerton (a lesser waste of time/money?) and paid $75 for a piece. I drove back on Chuckanut Drive and stopped at Baskin Robbins in Mount Vernon to make it a proper joy ride.
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Jackie



Joined: 18 Oct 2015
Posts: 78
City/Region: Ketchikan
State or Province: AK
C-Dory Year: 2008
C-Dory Model: 16 Cruiser
Vessel Name: Lil' Bit
Photos: Lil Bit
PostPosted: Thu May 21, 2020 1:35 pm    Post subject: Reply with quote

Teufel, please keep me informed on the Colorado supplier when you find out the cost. I contacted CoreLite and their 1.5" only comes in rigid sheets. I'm thinking Bob's suggestion of two layers of 3/4 inch might work best for me as I have a pretty good curve to fill in the bow. The wide openings of the kerfs as they curved there (and weren't filled) definitely added to the water migration. 3/4 inch wouldn't open so wide and would be easier to fill.

I don't think switching to a balsa alternative would work for me. I rounded the numbers up for safety, but I have about 28 square feet of core removed! I don't want to mess with different stiffnesses in the core so had better stick with matching my materials.

I will call C-Dory in Washington as it would be easiest for them to ship to the barge. Anything big is best barged to me.

Good luck as you keep at it! I spent three years in Germany during my service time. I was in the Army from 1976 - 1981.
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Barry Rietz



Joined: 21 Jun 2006
Posts: 267
City/Region: Sierra Vista
State or Province: AZ
PostPosted: Thu May 21, 2020 10:26 pm    Post subject: Rotten to the Core Reply with quote

This company has a comprehensive list of balsa and foam core materials in smaller size panels that would suit your application:
http://www.fiberglasssupply.com/
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Moxieabs



Joined: 02 Nov 2003
Posts: 183
City/Region: Cape Neddick
State or Province: ME
C-Dory Year: 2003
C-Dory Model: 22 Cruiser
Vessel Name: Widget
Photos: Widget
PostPosted: Fri May 22, 2020 8:43 pm    Post subject: Reply with quote

Jackie,
Unrelated to balsa core, but I was in 3rd Armor, Hanau '76-80. Where were you?

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Teufelshunde



Joined: 27 Aug 2019
Posts: 117
City/Region: Sebastopol
State or Province: CA
C-Dory Year: 1987
C-Dory Model: 22 Angler
Vessel Name: Fish Wisher
Photos: Fishwisher
PostPosted: Sun May 24, 2020 5:39 pm    Post subject: Reply with quote

Jackie wrote:
Teufel, please keep me informed on the Colorado supplier when you find out the cost. I contacted CoreLite and their 1.5" only comes in rigid sheets. I'm thinking Bob's suggestion of two layers of 3/4 inch might work best for me as I have a pretty good curve to fill in the bow. The wide openings of the kerfs as they curved there (and weren't filled) definitely added to the water migration. 3/4 inch wouldn't open so wide and would be easier to fill.

I don't think switching to a balsa alternative would work for me. I rounded the numbers up for safety, but I have about 28 square feet of core removed! I don't want to mess with different stiffnesses in the core so had better stick with matching my materials.

I will call C-Dory in Washington as it would be easiest for them to ship to the barge. Anything big is best barged to me.

Good luck as you keep at it! I spent three years in Germany during my service time. I was in the Army from 1976 - 1981.


30”x30” x1-1/2 inch thick is $165 + shipping - I need two of that size so the cost is $395 Shocked then I saw Barry’s post today and put a call into the supplier he suggested ( thanks Barry). I also posted pictures of the second half of the detour on the starboard side in my album.
We will see how it goes!
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thataway



Joined: 02 Nov 2003
Posts: 17792
City/Region: Pensacola
State or Province: FL
C-Dory Year: 2007
C-Dory Model: 25 Cruiser
Vessel Name: thataway
Photos: Thataway
PostPosted: Sun May 24, 2020 10:04 pm    Post subject: Reply with quote

At that price I would go with two 3/4" pieces--just put a layer of mat between if using polyester, or thin cloth or epoxy comparable mat, if using epoxy.

Even going to Jamestown Marine two 2' x 4' pieces would be $120 plus shipping. 30 x 30 = 900 sq inches, 24 x 48 = 1152 sq inches... 4 sheets would be $240 vs $395.. (plus shipping)

There are going to probably be cheaper places.
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Teufelshunde



Joined: 27 Aug 2019
Posts: 117
City/Region: Sebastopol
State or Province: CA
C-Dory Year: 1987
C-Dory Model: 22 Angler
Vessel Name: Fish Wisher
Photos: Fishwisher
PostPosted: Mon May 25, 2020 12:43 am    Post subject: Reply with quote

thataway wrote:
At that price I would go with two 3/4" pieces--just put a layer of mat between if using polyester, or thin cloth or epoxy comparable mat, if using epoxy.

Even going to Jamestown Marine two 2' x 4' pieces would be $120 plus shipping. 30 x 30 = 900 sq inches, 24 x 48 = 1152 sq inches... 4 sheets would be $240 vs $395.. (plus shipping)

There are going to probably be cheaper places.


Thanks Bob - I should get a callback on Tuesday and see what their pricing is.
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