Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 15-02-2016, 17:16   #31
Senior Cruiser

Cruisers Forum Supporter

Join Date: Mar 2007
Location: Santa Cruz
Boat: Boatless Again
Posts: 3,783
Re: Gelcoat can be successfully applied over Epoxy repairs

Quote:
Originally Posted by minaret View Post
As I said, haven't seen one yet. And I often do poly on poly repairs in major structural work. As in, the boat went on the rocks and is missing large portions of the hull type work. Don't know a single pro who would approach such a major structural repair in epoxy. Not one. And I went to school for this, have a degree in it, and know just about everybody worth anything in the business in my area. Every failed secondary bond I've ever seen was due to a total lack of prep work, because they were actually trying to get a primary bond and missed the window. Never seen a single failed secondary bond with grinder marks under it. Ever. This means that wasn't a secondary bond at all.
I've seen a lot of tabbing popped loose which is poly on poly. Of course on Bene's its poly on gelcoat....
__________________

__________________
donradcliffe is offline   Reply With Quote
Old 15-02-2016, 17:36   #32
Resin Head
 
minaret's Avatar

Cruisers Forum Supporter

Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 6,836
Images: 52
Re: Gelcoat can be successfully applied over Epoxy repairs

Quote:
Originally Posted by donradcliffe View Post
I've seen a lot of tabbing popped loose which is poly on poly. Of course on Bene's its poly on gelcoat....


Which, as I said, is a case of poor or non existent prep work.
__________________

__________________
O you who turn the wheel and look to windward,

Consider Phlebas, who was once handsome and tall as you.
minaret is offline   Reply With Quote
Old 15-02-2016, 17:51   #33
smj
Registered User

Join Date: Nov 2007
Location: galveston tx.
Boat: Searunner 38 catamaran
Posts: 2,868
Re: Gelcoat can be successfully applied over Epoxy repairs

Quote:
Originally Posted by Exile View Post
I'm curious what you then used as a topcoat for your extensions. Gel? Paint?



In general, if you use epoxy for minor repairs on a gel deck, can you bypass using 545 if you then use an epoxy based paint to try & match the gel? For minor stuff, I've used epoxy, but also gel with some Cabosil mixed in as a filler/thickener. So long as I got the color matching right (terrible at first but improving . . . maybe), then using gel alone seemed to eliminate a lot of the work & uncertainty of getting gel applied over epoxy.

We used paint. It matched up well with the gelcoat and in my opinion the epoxy gave us a far superior structural job.


Sent from my iPad using Cruisers Sailing Forum
__________________
smj is offline   Reply With Quote
Old 15-02-2016, 17:53   #34
smj
Registered User

Join Date: Nov 2007
Location: galveston tx.
Boat: Searunner 38 catamaran
Posts: 2,868
Re: Gelcoat can be successfully applied over Epoxy repairs

Quote:
Originally Posted by donradcliffe View Post
I've seen a lot of tabbing popped loose which is poly on poly. Of course on Bene's its poly on gelcoat....

I've also seen a lot of tabbing broken loose, poly on poly. A pretty well known problem when you use poly as a secondary bond.


Sent from my iPad using Cruisers Sailing Forum
__________________
smj is offline   Reply With Quote
Old 15-02-2016, 18:38   #35
Registered User
 
Reefmagnet's Avatar

Join Date: May 2008
Location: puɐןsuǝǝnb 'ʎɐʞɔɐɯ
Boat: Nantucket Island 33
Posts: 2,651
Re: Gelcoat can be successfully applied over Epoxy repairs

I think poly on poly has a lot to do with prep. If the wax isn't removed then the strength of the bond will be seriously reduced. I just went through an exercise mechanically removing both old polyester and old epoxy from my boat basically with a hammer and chisel and I actually found the epoxy to be both more brittle and easier to chip away. The polyester was tenacious and there was no separation of tabbing, even against some area of dry-rotted plywood. Admittedly, the epoxy looked more like araldite and is probably over 30 years old (as was the polyester).
__________________
Reefmagnet is offline   Reply With Quote
Old 15-02-2016, 18:44   #36
Registered User
 
Exile's Avatar

Join Date: Sep 2010
Location: Land of Disenchantment
Boat: Bristol 47.7
Posts: 2,411
Re: Gelcoat can be successfully applied over Epoxy repairs

Quote:
Originally Posted by smj View Post
We used paint. It matched up well with the gelcoat and in my opinion the epoxy gave us a far superior structural job.
This seems to be one of those perennial debates where sometimes even the experts disagree. Heck, there's even a section of the West Epoxy Systems manual devoted to it. Countless forum threads I'm sure.

In my case, I've addressed mostly cosmetic deck repairs both ways at this point, so time will tell. For non-structural issues, it seems that epoxy requires an extra finishing step which is always nice to avoid when practicable. A couple of years ago, and after enduring countless issues with my centerboard apparatus & below waterline sheave boxes, I decided to secure the board up into the keel and glass over the slot. A vulnerable area, obviously, and after a lot of research I ultimately went with the recommendation of the yard techs to use poly resin vs. epoxy. The finishing in this case wouldn't have mattered, of course, since it amounted to 3 coats of epoxy barrier and 2-3 coats of bottom paint.

The rationale of the techs who did the job was the same as Neil & Minaret, namely better to use the same materials the boat was constructed with originally. This amounted to using poly resin with 2 layers of 1408 mat/biax heavy glass, then 2 layers of satin weave cloth, and then a 3rd layer of 1408 applied to the middle section. I witnessed a LOT of grinding & prep work (laying on their backs & grinding uphill -- didn't look fun). No leaks or weeps in 2 years, but I'll see how she looks this spring after haul-out. Doesn't mean epoxy wouldn't have worked just as well, of course. Just hoping I made the right choice.
__________________
Exile is online now   Reply With Quote
Old 15-02-2016, 18:51   #37
Registered User

Join Date: Dec 2007
Location: Duluth,Minnesota
Boat: Lindenberg 26 & Aloha 8.2
Posts: 956
Re: Gelcoat can be successfully applied over Epoxy repairs

Quote:
Originally Posted by smj View Post
I've also seen a lot of tabbing broken loose, poly on poly. A pretty well known problem when you use poly as a secondary bond.


Sent from my iPad using Cruisers Sailing Forum
Must be a lot of crappy repair guys down your way. Ive seen my share of failed poly tabbing myself but I have the experience to recognize poor prep and don't blame the materials. I cant remember seeing a properly done repair fail with poly or epoxy. To many amateurs read the West system publications and don't have the experience to recognize that every method they propose is aimed at consuming mass quantities of their product. The same kind of lack of knowledge leads people to blame the balsa when they see a rotted balsa core when it is always the fault of human negligence.
__________________
clockwork orange is offline   Reply With Quote
Old 15-02-2016, 19:29   #38
smj
Registered User

Join Date: Nov 2007
Location: galveston tx.
Boat: Searunner 38 catamaran
Posts: 2,868
Re: Gelcoat can be successfully applied over Epoxy repairs

Quote:
Originally Posted by clockwork orange View Post
Must be a lot of crappy repair guys down your way. Ive seen my share of failed poly tabbing myself but I have the experience to recognize poor prep and don't blame the materials. I cant remember seeing a properly done repair fail with poly or epoxy. To many amateurs read the West system publications and don't have the experience to recognize that every method they propose is aimed at consuming mass quantities of their product. The same kind of lack of knowledge leads people to blame the balsa when they see a rotted balsa core when it is always the fault of human negligence.

No lack of knowledge, epoxy is well known to have better adhesion qualities than polyester, especially when trying to adhere to cured polyester. Do as you wish, I will stick to the product that has been continuously tested and come out on top. I would say there are to many old school glass men that don't know the superior qualities of epoxy, and may be to old to learn. Please bring on the publications that state polyester has superior secondary bonds as compared to epoxy.


Sent from my iPad using Cruisers Sailing Forum
__________________
smj is offline   Reply With Quote
Old 15-02-2016, 19:39   #39
Registered User
 
Exile's Avatar

Join Date: Sep 2010
Location: Land of Disenchantment
Boat: Bristol 47.7
Posts: 2,411
Re: Gelcoat can be successfully applied over Epoxy repairs

Quote:
Originally Posted by clockwork orange View Post
Must be a lot of crappy repair guys down your way. Ive seen my share of failed poly tabbing myself but I have the experience to recognize poor prep and don't blame the materials. I cant remember seeing a properly done repair fail with poly or epoxy. To many amateurs read the West system publications and don't have the experience to recognize that every method they propose is aimed at consuming mass quantities of their product. The same kind of lack of knowledge leads people to blame the balsa when they see a rotted balsa core when it is always the fault of human negligence.
True enough. The West Systems manuals & videos certainly try and minimize the problem with anime blush & adherence of gelcoat, for example. A lot of conflicting info out there. Can't even begin to tell ya how much contradictory advice I've gotten on the best way to maintain my Awlgrip topsides.
__________________
Exile is online now   Reply With Quote
Old 15-02-2016, 19:52   #40
smj
Registered User

Join Date: Nov 2007
Location: galveston tx.
Boat: Searunner 38 catamaran
Posts: 2,868
Re: Gelcoat can be successfully applied over Epoxy repairs

http://www.amtcomposites.co.za/sites...0Polyester.pdf
http://www.boatus.com/boattech/casey/polyster-epoxy.asp
http://www.compresdev.co.uk/CRD%20Th...0Polyester.pdf
http://www.azom.com/article.aspx?ArticleID=997
I could go on but it's obvious. if you have to have a gelcoat finish over superior structural strength then use polyester.


Sent from my iPad using Cruisers Sailing Forum
__________________
smj is offline   Reply With Quote
Old 16-02-2016, 01:53   #41
Registered User
 
neilpride's Avatar

Join Date: Jul 2009
Location: in the world
Boat: csy 44 tall rig.
Posts: 2,745
Re: Gelcoat can be successfully applied over Epoxy repairs

Quote:
Originally Posted by smj View Post
No lack of knowledge, epoxy is well known to have better adhesion qualities than polyester, especially when trying to adhere to cured polyester. Do as you wish, I will stick to the product that has been continuously tested and come out on top. I would say there are to many old school glass men that don't know the superior qualities of epoxy, and may be to old to learn. Please bring on the publications that state polyester has superior secondary bonds as compared to epoxy.


Sent from my iPad using Cruisers Sailing Forum
Insurance companys most of the time ask for OEM materials in the repairs, i see lots of holed boats , broken, from the last canes passing the islands , all this boats repaired using Poly and gel and not a single failure, to bad to paint a stern extension when the boat have gel on topsides , if you can match a gel extension with the surrounding gel this is the best aproach in my opinion,, tabbing is another history and i see lots of broken joints but honestly Ply and poly ,and the prep is not always good.

No one is saying epoxy is weaker , but if you can make a repair or upgrade using the same material much better.
__________________
neilpride is offline   Reply With Quote
Old 16-02-2016, 04:09   #42
Resin Head
 
minaret's Avatar

Cruisers Forum Supporter

Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 6,836
Images: 52
Re: Gelcoat can be successfully applied over Epoxy repairs

Quote:
Originally Posted by neilpride View Post
Insurance companys most of the time ask for OEM materials in the repairs, i see lots of holed boats , broken, from the last canes passing the islands , all this boats repaired using Poly and gel and not a single failure, to bad to paint a stern extension when the boat have gel on topsides , if you can match a gel extension with the surrounding gel this is the best aproach in my opinion,, tabbing is another history and i see lots of broken joints but honestly Ply and poly ,and the prep is not always good.

No one is saying epoxy is weaker , but if you can make a repair or upgrade using the same material much better.


And faster, and cheaper. And paint matching gel!? That's ridiculous. Even if the color matches, the gloss and depth of image will be totally different, and will quickly age completely differently.

I too have always had insurance co.'s ask for OEM repairs. They are well aware of the issues with dissimilar materials.
__________________
O you who turn the wheel and look to windward,

Consider Phlebas, who was once handsome and tall as you.
minaret is offline   Reply With Quote
Old 16-02-2016, 04:11   #43
Resin Head
 
minaret's Avatar

Cruisers Forum Supporter

Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 6,836
Images: 52
Re: Gelcoat can be successfully applied over Epoxy repairs

Quote:
Originally Posted by smj View Post
No lack of knowledge, epoxy is well known to have better adhesion qualities than polyester, especially when trying to adhere to cured polyester. Do as you wish, I will stick to the product that has been continuously tested and come out on top. I would say there are to many old school glass men that don't know the superior qualities of epoxy, and may be to old to learn. Please bring on the publications that state polyester has superior secondary bonds as compared to epoxy.


Sent from my iPad using Cruisers Sailing Forum



Come on. The last custom epoxy boat I built cost 12.8 million dollars to complete, all vacuum bagged carbon fiber and epoxy. I'd guess I've used at least 10,000 gallons of epoxy in my career, of all brands, including many specialty laminating resins which were not released to the general public at the time. Your accusation is ridiculous.
__________________
O you who turn the wheel and look to windward,

Consider Phlebas, who was once handsome and tall as you.
minaret is offline   Reply With Quote
Old 16-02-2016, 05:24   #44
Moderator
 
HappyMdRSailor's Avatar

Cruisers Forum Supporter

Join Date: May 2008
Location: North Mississippi
Boat: 48 Wauquiez Pilot Saloon-C22 Chrysler Sunpiper- 19 Potter-Preparing to cruise w/my girl
Posts: 5,969
Re: Gelcoat can be successfully applied over Epoxy repairs

Quote:
Originally Posted by StuM View Post
That extra space made me look twice! I first read that as an enquiry about his dress sense
Quote:
Originally Posted by Jim Cate View Post
OOOpsss! Bloody keyboard...

Good catch, Stu!

Jim
HAHA! That was funny you two !

Quote:
Originally Posted by minaret View Post
545.

Not really a normal hat, tie and coat guy. Unless you count fullface respirator for hat, forced air line for tie, and a Tyvek for coat!
Bahdumpdump

Quote:
Originally Posted by neilpride View Post
Same here, I love work with Epoxy, but we work mainly with Poly, to match OEM materials and to avoid dismilar materials in tricky spots, hard spots... Last large job, a 5 ft stern extensions in a multi, made in poly and gelcoat, secondary bond obviously .. no problems at all.....
Just adding another vote after minaret's 1st, and Neil's 2nd above... I ALSO like working with epoxy more than poly... but don't eat soup with a fork... So I... like the other guys use the right tool for the job....

(ps... I;m barely worthy of cleaning up after prep grinding for the aforementioned rock stars...)
__________________
In the harsh marine environment, something is always in need of repair...

Mai Tai's fix everything...
HappyMdRSailor is offline   Reply With Quote
Old 16-02-2016, 05:43   #45
Moderator
 
HappyMdRSailor's Avatar

Cruisers Forum Supporter

Join Date: May 2008
Location: North Mississippi
Boat: 48 Wauquiez Pilot Saloon-C22 Chrysler Sunpiper- 19 Potter-Preparing to cruise w/my girl
Posts: 5,969
Re: Gelcoat can be successfully applied over Epoxy repairs

Quote:
Originally Posted by minaret View Post
And faster, and cheaper. And paint matching gel!? That's ridiculous. Even if the color matches, the gloss and depth of image will be totally different, and will quickly age completely differently.

I too have always had insurance co.'s ask for OEM repairs. They are well aware of the issues with dissimilar materials.
Hmm... paint matching gel you say...

Quote:
Originally Posted by minaret View Post
Come on. The last custom epoxy boat I built cost 12.8 million dollars to complete, all vacuum bagged carbon fiber and epoxy. I'd guess I've used at least 10,000 gallons of epoxy in my career, of all brands, including many specialty laminating resins which were not released to the general public at the time. Your accusation is ridiculous.
Let's see... $12.8M-materials/$13.73hr (happy's lam labor rate)...
****licks thumb****
**pulls life expectancy actuarial tables**
"oh dear"
Uhm...


I'd probably trust the guy who's used over 1 MILLION dollars of just resin...

Some people can't be convinced...

Speaking of which... Wonder what's going on in the bene rudder thread...
__________________

__________________
In the harsh marine environment, something is always in need of repair...

Mai Tai's fix everything...
HappyMdRSailor is offline   Reply With Quote
Reply

Tags
epoxy, gelcoat, repairs

Thread Tools
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
So West System Epoxy Resin Can Be Used As A Complete Substitute For Gelcoat ? albergsailor Monohull Sailboats 62 20-08-2012 22:49
Got Her ! Catalac 900 Successfully Delivered simonmd Multihull Sailboats 15 03-10-2011 07:10
Gelcoat applied, no catalyst used D.D. Construction, Maintenance & Refit 4 03-07-2011 10:59
Drilling into Gelcoat Successfully gbanker Construction, Maintenance & Refit 11 10-01-2010 06:23
For those who have successfully used an artificial horizon Seadogg Navigation 0 27-08-2008 07:44


Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 21:42.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.