How long will a polyethylene boat last ? - Page 2 - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Boat Review and Purchase Forum
 Not a Member? 


Reply
 
LinkBack Thread Tools
  #11  
Old 01-23-2009
Senior Member
 
Join Date: Feb 2006
Location: Florida, US northeast
Posts: 100
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
Dick Pluta is on a distinguished road
Here's commentary from a plastic engineer. At a molecular level plastics are long chains of molecules like ethylene and propylene, thus poly-ethylene, etc. Sort of like a molecular dish of spaghetti. UV radiation breaks these chains and, eventually, returns them to their original state. In polyethylene, for example, this is a gas. In reality it never gets this far but as the chains get shorter the stuff gets weaker. Think the thin plastic webbing on cheap lawn chairs. A couple of years in the sun and they are gone.

There are two ways to minimize this damage, UV absorbers and bulk. UV absorbers "eat" the UV before it gets to the plastic molecule but, eventually, these get used up. Bulk keeps the damage on the surface, with the damaged layer protecting those underneath. That faded stuff is degraded plastic. In theory, a thick poly hull could last for a long time, although it would look bad.

Boat manufacturers aren't going to put any more material in a hull than they need for strength, so there goes bulk. UV absorbers are expensive and there won't be any more than is absolutely necessary. Anyway, they get consumed when doing their job so it's only a matter of time before they stop working.

I'd consider a plastic boat as a disposable item. When it gets old it's used up. I'd call a very faded boat old. Like a rotted wood boat, repair is expensive and impractical. Even worse, with inexpensive plastics, like PE and PP, repair with paint or adhesives isn't even possible. Nothing sticks. It's not for nothing that PP and PE are used for lab ware. Nothing touches them.

How long that takes depends. Only taken out of the garage when used a couple of times a year? Ten years is probably OK. Left out in the sun on a Florida beach? Three years is probably too many. Scratch the surface with your fingernail. If anything comes off, it's way too late. If it's badly faded, it's well on it's way out.

Dick Pluta
AEGEA
Nassau, Bahamas
Reply With Quote Share with Facebook
  #12  
Old 01-23-2009
Jeff_H's Avatar
Moderator
 
Join Date: Feb 2000
Location: Annapolis, Md
Posts: 6,582
Thanks: 5
Thanked 95 Times in 71 Posts
Rep Power: 10
Jeff_H has a spectacular aura about Jeff_H has a spectacular aura about Jeff_H has a spectacular aura about
I am sure that the answer to this question very much varies with the materials used, the molding method and the boat's exposure, but I still regularly use a 35 year old polyethelyne Sportyak II dinghy that I have owned for over 25 years and which has spent most of its life stored out in the sun either on my dock or leaned against the wall of my house. Its had pretty hard use and its still in good, but ugly shape (began ugly and has not gotten prettier with age). I can't beleive they still make these things.
Reply With Quote Share with Facebook
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Mr. Renovation GoodOldBoat Good Old Boat 2 12-28-2009 02:56 PM
Trailering? Pick a Boat Bruce Caldwell Cruising Articles 0 07-22-2004 08:00 PM
Rust Never Sleeps John Kretschmer Gear and Maintenance Articles 0 02-27-2003 07:00 PM
The New Racing Rules Dobbs Davis Racing Articles 0 04-04-2001 08:00 PM
The Balance of Hull and Sails Steve Colgate Seamanship Articles 0 05-25-2000 08:00 PM


All times are GMT -4. The time now is 05:07 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.