Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 28-05-2015, 14:03   #16
Registered User

Join Date: Sep 2011
Location: Durban South Africa
Boat: WALLER MKII CAT 11M
Posts: 103
Re: Epoxy / Fiberglass Glass Marine Ply sheathing help

Quote:
Originally Posted by s/v Jedi View Post
I always do a dry layup, i.e. put the fiberglass cloth on the plywood, then pour the mixed epoxy resin + hardener on the center and use a plastic spreader to work the resin further out towards the sides. The fiberglass should turn transparant very quickly while doing this. Here are some pictures:

the moment we pour the mixed epoxy in the center:


finished spreading it out:


That's exactly how I have been apply the epoxy and glass except adding a layer of peel ply to get a good Finnish. For minimum
Of sanding on finish coat...ie no blush to worry about for next layer or painting
__________________

__________________
delcrest is offline   Reply With Quote
Old 28-05-2015, 14:23   #17
Senior Cruiser
 
atoll's Avatar

Cruisers Forum Supporter

Join Date: Mar 2010
Location: gettin naughty on the beach in cornwall
Boat: 63 custom alloy sloop,macwester26,prout snowgoose 37 elite catamaran!
Posts: 9,310
Images: 75
Re: Epoxy / Fiberglass Glass Marine Ply sheathing help

Quote:
Originally Posted by delcrest View Post
That's exactly how I have been apply the epoxy and glass except adding a layer of peel ply to get a good Finnish. For minimum
Of sanding on finish coat...ie no blush to worry about for next layer or painting
what sort of humidity do you have?

sounds like either you ply or cloth is damp.

have you tried thickening the epoxy 2-3% with colloidal silica for better adhesion?
__________________

__________________
my catamaran building project updates http://www.cruisersforum.com/forums/...36#post2502136
atoll is offline   Reply With Quote
Old 28-05-2015, 17:03   #18
Do… or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 9,198
Re: Epoxy / Fiberglass Glass Marine Ply sheathing help

Quote:
Originally Posted by delcrest View Post
That's exactly how I have been apply the epoxy and glass except adding a layer of peel ply to get a good Finnish. For minimum
Of sanding on finish coat...ie no blush to worry about for next layer or painting
With this single layer of cloth, when I grab the overhang with piers and start pulling, I tear off pieces of wood from the Bruynzeel marine ply so the bond is stronger than the wood.

I would try a little test piece without the peel-ply and a dry layup. Make sure everything is clean, I vacuum the plywood, and then either put it in the sun for a bit or heat it with a heat gun. This will later draw the epoxy further into the wood fibers as it cools, plus it prevents bubbles from exothermic heat.

I have used all the wrong kinds of fiberglass with West System and MAS epoxies and even then not a problem. What brands of epoxy did you try? I have used a local brand once and got weird things much like you describe.
__________________
s/v Jedi is offline   Reply With Quote
Old 28-05-2015, 17:30   #19
Registered User

Join Date: Nov 2013
Location: Slidell, La.
Boat: Morgan Classic 33
Posts: 1,101
Re: Epoxy / Fiberglass Glass Marine Ply sheathing help

Certainly sounds like a sizing/resin compatablity issue. Apparently there are many, many different sizings for the many, many different variables of the manufacturing processes available.


Sizing Up Fiber Sizings : CompositesWorld


It's not unknown for material to get mislabeled or misboxed, so even if the box or roll you have says it's one thing, it may not be necessarily so...


When you peel up the cloth, is there epoxy adhering to the underside of the cloth?
__________________
jimbunyard is offline   Reply With Quote
Old 28-05-2015, 17:58   #20
Registered User
 
nimblemotors's Avatar

Join Date: Apr 2011
Location: Sacramento, California
Boat: Solar 40ft Cat :)
Posts: 1,557
Re: Epoxy / Fiberglass Glass Marine Ply sheathing help

My guess is also the plywood has moisture in it.
__________________
JackB
MiniMPPT Solar Controller
nimblemotors is offline   Reply With Quote
Old 28-05-2015, 18:21   #21
Registered User
 
Nicholson58's Avatar

Join Date: Jan 2011
Location: Live aboard
Boat: Camper & Nicholson58 Ketch - ROXY Traverse City, Michigan No.668283
Posts: 3,466
Images: 83
Re: Epoxy / Fiberglass Glass Marine Ply sheathing help

My only epoxy for all builds & repairs is US Composites 635 THIN resin. Lower cost; no amine blush; very long pot life and superior wet-out. They also are a good source for glass, Microballoons, carbon fiber etc. Fiberglass , Epoxy , Composites, Carbon Fiber - U.S. Composites, Inc.

I use no other epoxy.
__________________
Nicholson58 is offline   Reply With Quote
Old 28-05-2015, 22:59   #22
Registered User

Join Date: Sep 2011
Location: Durban South Africa
Boat: WALLER MKII CAT 11M
Posts: 103
Re: Epoxy / Fiberglass Glass Marine Ply sheathing help

Quote:
Originally Posted by jimbunyard View Post
Certainly sounds like a sizing/resin compatablity issue. Apparently there are many, many different sizings for the many, many different variables of the manufacturing processes available.


Sizing Up Fiber Sizings : CompositesWorld


It's not unknown for material to get mislabeled or misboxed, so even if the box or roll you have says it's one thing, it may not be necessarily so...


When you peel up the cloth, is there epoxy adhering to the underside of the cloth?

NO the epoxy is left on the ply wood with the impression of the cloth on the epoxy, the same epoxy has been used for all the construction to date and has worked VERY well
All destructive test done between wood / plywood have been excellent , joints breaking and pulling the wood/ply layers apart excellent results!!
While waiting for the independent laboratory test I have located other epoxy suppliers and will do some more testing.....in the meantime the manufacturers / suppliers can't give me an answer
By the way I live in South Africa not to much humidity or cold weather
__________________
delcrest is offline   Reply With Quote
Old 28-05-2015, 23:09   #23
Registered User

Join Date: Sep 2011
Location: Durban South Africa
Boat: WALLER MKII CAT 11M
Posts: 103
Re: Epoxy / Fiberglass Glass Marine Ply sheathing help

Quote:
Originally Posted by delcrest View Post
NO the epoxy is left on the ply wood with the impression of the cloth on the epoxy, the same epoxy has been used for all the construction to date and has worked VERY well
All destructive test done between wood / plywood have been excellent , joints breaking and pulling the wood/ply layers apart excellent results!!
While waiting for the independent laboratory test I have located other epoxy suppliers and will do some more testing.....in the meantime the manufacturers / suppliers can't give me an answer
By the way I live in South Africa not to much humidity or cold weather
Sizing Up Fiber Sizings : CompositesWorld

I believe this incompatibility between glass and epoxy as described in the article above is the problem, thank you for your excellent post
__________________

__________________
delcrest is offline   Reply With Quote
Reply

Tags
epoxy, fiberglass, marine

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
Re-Sheathing Backstays cburger Deck hardware: Rigging, Sails & Hoisting 12 04-04-2012 13:48
Copper Sheathing itdave5 Construction, Maintenance & Refit 1 17-07-2011 10:00
The Strength of Marine Ply and Cold-Molded Ply alanvdh Monohull Sailboats 50 11-02-2011 15:42
Marine ply VS Pressure treated ply easterly Construction, Maintenance & Refit 12 09-09-2008 12:26
Alluminum sheathing emeraldsea Construction, Maintenance & Refit 5 24-01-2008 19:16



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 14:06.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.