Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 08-04-2018, 16:41   #31
Senior Cruiser
 
skipmac's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: 29° 49.16’ N 82° 25.82’ W
Boat: Pearson 422
Posts: 16,306
Re: Wet balsa core repair options?

Quote:
Originally Posted by Terra Nova View Post
Plenty of misinformation here but this is so wrong. As if you can dry out wet balsa core in 15 minutes using a blow dryer!
Exactly.

Depending on how wet and how far into the deck it penetrates it could take days or weeks or it could never get totally dry.
__________________
The water is always bluer on the other side of the ocean.
Sometimes it's necessary to state the obvious for the benefit of the oblivious.
Rust is the poor man's Loctite.
skipmac is offline   Reply With Quote
Old 08-04-2018, 17:52   #32
cruiser

Join Date: Jan 2012
Location: Lake Ontario
Boat: Ontario 38 / Douglas 32 Mk II
Posts: 3,250
Re: Wet balsa core repair options?

Quote:
Originally Posted by Terra Nova View Post
Plenty of misinformation here but this is so wrong. As if you can dry out wet balsa core in 15 minutes using a blow dryer!
Incorrect assumption.

The purpose of using the blow drier and flushing with Methyl Hydrate is not to "dry out the balsa", but rather to quickly drive out moisture and remove slime and rot from the surfaces to have resin applied.

The idea that all wet balsa core must be removed for the composite to be sound is false.

There is no question that wet balsa is not as good as dry balsa; but wet sound balsa is no reason to require balsa removal and replacement.

Again, almost every 25 year old balsa cored boat has some moisture in the deck somewhere, and it can stay there forever and never be a problem. Only where it has rotted or delaminated does it need to be repaired.

Preventing more moisture from getting in is key.
ramblinrod is offline   Reply With Quote
Old 08-04-2018, 19:18   #33
Registered User

Join Date: May 2014
Location: USA
Boat: 41' yawl
Posts: 1,187
Re: Wet balsa core repair options?

Quote:
Originally Posted by ramblinrod View Post
The purpose of using the blow drier and flushing with Methyl Hydrate is not to "dry out the balsa", but rather to quickly drive out moisture and remove slime and rot from the surfaces to have resin applied.


But if the surrounding balsa is wet, how long do you suppose your superficial dry spot is going to stay dry?

Is that fast hardener you are using, or only slow? Do you feel lucky? [emoji23]
chris95040 is offline   Reply With Quote
Old 08-04-2018, 22:11   #34
cruiser

Join Date: Jan 2012
Location: Lake Ontario
Boat: Ontario 38 / Douglas 32 Mk II
Posts: 3,250
Re: Wet balsa core repair options?

Quote:
Originally Posted by chris95040 View Post
But if the surrounding balsa is wet, how long do you suppose your superficial dry spot is going to stay dry?

Is that fast hardener you are using, or only slow? Do you feel lucky? [emoji23]
Balsa core is never dry.

Right from the balsa core factory the actual moisture content is around 10-15%.

I typically use cabosil thickened unwaxed Isopthalic polyester resin catalyzed with 0.5 to 1.5% MEKP based on temperature.

Luck has absolutely nothing to do with it. ;-)
ramblinrod is offline   Reply With Quote
Old 08-04-2018, 22:31   #35
Registered User

Join Date: Feb 2011
Location: Virginia
Boat: Shopping for a 30-ish cat
Posts: 418
Re: Wet balsa core repair options?

Quote:
Originally Posted by ramblinrod View Post
...I typically use cabosil thickened unwaxed Isopthalic polyester resin catalyzed with 0.5 to 1.5% MEKP based on temperature...
May I ask why you choose polyester over epoxy resins?
prof_mariner is offline   Reply With Quote
Old 09-04-2018, 03:47   #36
Registered User

Join Date: May 2014
Location: USA
Boat: 41' yawl
Posts: 1,187
Wet balsa core repair options?

Quote:
Originally Posted by ramblinrod View Post
Balsa core is never dry.



Right from the balsa core factory the actual moisture content is around 10-15%.


Obviously none of us are talking about the natural moisture content in the wood.

Do you dry off after taking a shower, or just go ahead and get dressed? I mean, our bodies are about 66% water, right? [emoji849]
chris95040 is offline   Reply With Quote
Old 09-04-2018, 08:47   #37
cruiser

Join Date: Jan 2012
Location: Lake Ontario
Boat: Ontario 38 / Douglas 32 Mk II
Posts: 3,250
Re: Wet balsa core repair options?

Quote:
Originally Posted by prof_mariner View Post
May I ask why you choose polyester over epoxy resins?
For every job, I choose the resin I believe is best suited for the application, based on my 35 years of experience using polyester and epoxy resins.

For boats made of polyester resin (most I encounter), if there is no compelling reason to use epoxy resin, I tend toward polyester, if for no other reason than to help avoid epoxy resin sensitization, for myself, my customer, their family, and their crew.

Again, this is just one reason; there are many issues to be considered.

For polyester FRP repair, I almost always use polyester resin, especially inside the boat, and anywhere matching the polyester resin gelcoat is desired.

When epoxy resin is the clear winner, that is what I use.

Filling and fairing cast iron and lead keels, epoxy primer or barrier coat before anti-fouling, and epoxy primer before 2-pack topside paints, are my most common uses of epoxy resins.

I rarely encounter epoxy cold moulded boats, as few production models exist in our market, and most DIY builders repair their own, but that is another application where epoxy resin would be the clear resin of choice.
ramblinrod is offline   Reply With Quote
Old 09-04-2018, 08:59   #38
cruiser

Join Date: Jan 2012
Location: Lake Ontario
Boat: Ontario 38 / Douglas 32 Mk II
Posts: 3,250
Re: Wet balsa core repair options?

Quote:
Originally Posted by chris95040 View Post
Obviously none of us are talking about the natural moisture content in the wood.

Do you dry off after taking a shower, or just go ahead and get dressed? I mean, our bodies are about 66% water, right? [emoji849]
Training a blow dryer on the surface and flushing with Methyl Hydrate a couple times is akin to your showering and towelling off analogy I s'pose.

Anyway, it works.
ramblinrod is offline   Reply With Quote
Old 09-04-2018, 09:05   #39
Registered User
 
Cheechako's Avatar

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 25,477
Re: Wet balsa core repair options?

The problem I see is not the Injectadeck product itself, it's what's inside the deck. Water and wood mush sometimes. I don't think just injecting something into that garbage is a "fix" at all. The stuff I took out of my 44 footer V berth was black rotten plywood. It came out as stringy smelly mush.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 09-04-2018, 10:14   #40
cruiser

Join Date: Jan 2017
Boat: Retired from CF
Posts: 13,317
Re: Wet balsa core repair options?

Just a reminder, in a public forum no one knows you're a dog.

Sometimes those speaking with the most confidence are giving the falsest information and the worst advice.

You can get a feel for credibility when exposed to a member's posting history over time, so do your due diligence in the archives if someone comes out with radical claims that go against the elders' majority opinion.
john61ct is offline   Reply With Quote
Old 09-04-2018, 11:46   #41
cruiser

Join Date: Jan 2012
Location: Lake Ontario
Boat: Ontario 38 / Douglas 32 Mk II
Posts: 3,250
Re: Wet balsa core repair options?

Quote:
Originally Posted by john61ct View Post
Just a reminder, in a public forum no one knows you're a dog.

Sometimes those speaking with the most confidence are giving the falsest information and the worst advice.

You can get a feel for credibility when exposed to a member's posting history over time, so do your due diligence in the archives if someone comes out with radical claims that go against the elders' majority opinion.
I concur completely that one should always consider the source.

I advise my children, friends, and customers to do this every day.

Question the validity and integrity of every forum post, YouTube video, or manufacturers marketing propaganda.

To avoid deception and misinformation, apply critical thinking
ramblinrod is offline   Reply With Quote
Old 09-04-2018, 23:57   #42
Registered User
 
Scout 30's Avatar

Join Date: Oct 2014
Location: Florida
Boat: Scout 30
Posts: 3,112
Re: Wet balsa core repair options?

[QUOTE=ramblinrod;2612781]For every job, I choose the resin I believe is best suited for the application, based on my 35 years of experience using polyester and epoxy resins.

For boats made of polyester resin (most I encounter), if there is no compelling reason to use epoxy resin, I tend toward polyester, if for no other reason than to help avoid epoxy resin sensitization, for myself, my customer, their family, and their crew.


How noble. 35 years of experience & you don't know that sensitization only happens when you come in contact with uncured epoxy. Once epoxy is cured it is inert. You might make money squirting epoxy into wet decks or using polyester resin for secondary bonds because it's cheaper but you're not doing your customer or "their family" any favors.
Scout 30 is offline   Reply With Quote
Old 10-04-2018, 08:31   #43
Registered User

Join Date: Mar 2015
Location: Boston's North Shore
Boat: Pearson 10M
Posts: 839
Re: Wet balsa core repair options?

[QUOTE=Scout 30;2613155]
Quote:
Originally Posted by ramblinrod View Post
For every job, I choose the resin I believe is best suited for the application, based on my 35 years of experience using polyester and epoxy resins.

For boats made of polyester resin (most I encounter), if there is no compelling reason to use epoxy resin, I tend toward polyester, if for no other reason than to help avoid epoxy resin sensitization, for myself, my customer, their family, and their crew.


How noble. 35 years of experience & you don't know that sensitization only happens when you come in contact with uncured epoxy. Once epoxy is cured it is inert. You might make money squirting epoxy into wet decks or using polyester resin for secondary bonds because it's cheaper but you're not doing your customer or "their family" any favors.
I want to highlight the point made, polyester resin used to form secondary bonds is weaker than epoxy. A secondary bond if formed when attaching new resin to previously cured resin. Epoxy is superior to polyester when making secondary bonds.
The disadvantage to epoxy is it takes longer to cure.

Second point; leaving wet core in place will result in delamination if the deck is subject to freezing temperatures.

I strongly suggest ignoring the advice to use polyester resin for repairs.
guyrj33 is offline   Reply With Quote
Old 10-04-2018, 10:10   #44
cruiser

Join Date: Jan 2012
Location: Lake Ontario
Boat: Ontario 38 / Douglas 32 Mk II
Posts: 3,250
Re: Wet balsa core repair options?

[QUOTE=guyrj33;2613407]
Quote:
Originally Posted by Scout 30 View Post

I want to highlight the point made, polyester resin used to form secondary bonds is weaker than epoxy. A secondary bond if formed when attaching new resin to previously cured resin. Epoxy is superior to polyester when making secondary bonds.
The disadvantage to epoxy is it takes longer to cure.

Second point; leaving wet core in place will result in delamination if the deck is subject to freezing temperatures.

I strongly suggest ignoring the advice to use polyester resin for repairs.
I have seen lots of DIY projects destroyed, abandoned, made inferior, or costing way more than necessary, in materials, sweat equity, storage yard fees, and loss of use. In every case, the DIYer will swear their choices were justified.

Occasional an owner will hire us to clean up the mess they have created.

Any boat owner is free (maybe) to choose their marine service provider, as have many of my happy and loyal customers who when faced with a “the only solution is” proposition, sought a second opinion.

Of all of the polyester secondary bonds I have performed, I have not had one failure.

In my opinion, the adhesion strength difference of materials is much less than many believe, and irrelevant, when one assures the strength of materials chosen are adequate for the application.

Thank you for your input.

However, I will continue to offer my customers options that I am willing to stake my reputation on, and discuss the risks and benefits of each.
ramblinrod is offline   Reply With Quote
Old 11-04-2018, 07:42   #45
Registered User
 
Scout 30's Avatar

Join Date: Oct 2014
Location: Florida
Boat: Scout 30
Posts: 3,112
Re: Wet balsa core repair options?

Quote:
Originally Posted by Cheechako View Post
The problem I see is not the Injectadeck product itself, it's what's inside the deck. Water and wood mush sometimes. I don't think just injecting something into that garbage is a "fix" at all. The stuff I took out of my 44 footer V berth was black rotten plywood. It came out as stringy smelly mush.
I get what you're saying having done a similar repair myself. Supposedly that's exactly the kind of problem Injectadeck works best at solving. They say that the foam is attracted to moisture & the more the core is rotten the more the foam can displace it. In fact, if the core is dry you have to add water to it. Like you my first reaction was this is cutting a corner & that's never a good thing when boats are concerned. However, the more I've thought about it the more I think it would be worth trying. I've seen a few boats for sale recently, including a Krogen & a Tayana, that the sellers were having a hard time giving away due to extensive deck leaks & damage. If damage like that can be fixed in a much easier & more cost effective way there might be some really great deals out there.
Scout 30 is offline   Reply With Quote
Reply

Tags
core

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Bad News - Wet Balsa Core AJ_n_Audrey Construction, Maintenance & Refit 71 17-01-2018 05:43
Replacing wet balsa core phorvati Construction, Maintenance & Refit 77 26-08-2016 12:33
Using Epoxy for wet balsa core sustutt Construction, Maintenance & Refit 7 04-02-2014 16:30
To balsa core or not to balsa core? fbchristo Multihull Sailboats 135 04-02-2009 14:13

Advertise Here


All times are GMT -7. The time now is 05:52.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.