The Forestry Forum is sponsored in part by:

iDRY Vacuum Kilns


Forestry Forum
Sponsored by:


TimberKing Sawmills



Toll Free 1-800-582-0470

LogRite Tools



Norwood Industries Inc.




Your source for Portable Sawmills, Edgers, Resaws, Sharpeners, Setters, Bandsaw Blades and Sawmill Parts

EZ Boardwalk Sawmills. More Saw For Less Money!

STIHLDealers.com sponsored by Northeast STIHL


Woodland Sawmills

Peterson Swingmills

 KASCO SharpTech WoodMaxx Blades

Turbosawmill

Sawmill Exchange

Michigan Firewood, your BRUTE FORCE Authorized Dealer

Baker Products

ECHO-Bearcat

iDRY Wood Lumber Vacuum Drying for everyon

Nyle Kiln Dry Systems

Chainsawr, The Worlds Largest Inventory of Chainsaw Parts

Smith Sawmill Service



Author Topic: Epoxy theory....  (Read 3038 times)

0 Members and 3 Guests are viewing this topic.

Offline Smithkp

  • member
  • *
  • Posts: 40
  • Age: 52
  • Location: Chesapeake, VA
  • Gender: Male
  • I'm new!
    • Share Post
Epoxy theory....
« on: August 15, 2018, 01:46:39 PM »
I use a lot of epoxy to coat wood. I have this theory that if you encapsulate a board that has air dried, fully encapsulate it, will it crack, warp or rot? 

My brain says there will be no air exchange so moisture content will stay the same so no movement should be expected. But would it rot from the inside out? Doesn't rot require oxygen?

Very curious as to any answers one way or the other....
Anything worth doing is worth doing well.

Offline Ianab

  • Administrator
  • *****
  • Posts: 15054
  • Age: 59
  • Location: Stratford , New Zealand
  • Gender: Male
  • Marmite on toast is a real breakfast
    • Share Post
Re: Epoxy theory....
« Reply #1 on: August 15, 2018, 02:55:27 PM »
If wood is properly air dried it will have a moisture level well below 20%, which is what decay fungus or bacteria need to grow. So it won't rot unless water gets added.

But epoxy isn't 100% water resistant. It's still somewhat permeable to moisture, although it slows this down a Lot. So wood could still gradually dry out, and that could lead to warping or cracking.

So for that reason you want things properly dry before you apply any finish.
Weekend warrior, Peterson JP test pilot, Dolmar 7900 and Stihl MS310 saws and  the usual collection of power tools :)

Offline low_48

  • Senior Member
  • ****
  • Posts: 920
  • Age: 69
  • Location: Peoria, IL 61614
  • Gender: Male
    • Share Post
Re: Epoxy theory....
« Reply #2 on: August 15, 2018, 09:31:10 PM »
Epoxy is also very sensitive to ultraviolet light. It breaks down after being exposed. Most boat people add a coat or two of spar varnish over epoxy to help out. So sooner or latter, it will crack, warp, and rot. No finish is forever.

Offline Don P

  • Senior Member x2
  • *****
  • Posts: 8769
  • Location: Southwestern VA
  • Gender: Male
    • Share Post
    • Calculator Index
Re: Epoxy theory....
« Reply #3 on: August 15, 2018, 10:26:18 PM »
Then, once a film forming finish is breached, if liquid water can get into the crack it will diffuse into the wood. That moisture has to leave as a vapor and most of the wood surface is covered by a good vapor barrier. Then the moisture content rises because more liquid water is coming in than can evaporate from the surface. MC rises into the mid 20% range and then you are in the rot zone.

I've seen something like this in log homes. If the wood is covered with a water repellant but breathable finish, a stain, it repels most bulk water but can also dry fairly readily. As long as the wetting events aren't too frequent that works.

Then there are those completely painted cement chinked 1920's log cabins that seem to survive. The ones that have I think have been kept very well painted. That encapsulation you are talking about has been maintained.

I had a client that applied stain to the heavily weathering south side of his logs annually. It refreshed the look but the buildup of stain became a film and in that full sun exposure the logs had working checks. The finish had many places to admit water and became a compost bag with the wet logs inside. I scooped out the inside of the logs in places by hand.

My feeling is that encapsulation is great until it inevitably isn't fully encapsulating, then its worse than nothing.
The future is a foreign country, they will do things differently there - Simon Winchester

Offline Smithkp

  • member
  • *
  • Posts: 40
  • Age: 52
  • Location: Chesapeake, VA
  • Gender: Male
  • I'm new!
    • Share Post
Re: Epoxy theory....
« Reply #4 on: August 16, 2018, 07:45:52 AM »
Epoxy is also very sensitive to ultraviolet light. It breaks down after being exposed. Most boat people add a coat or two of spar varnish over epoxy to help out. So sooner or latter, it will crack, warp, and rot. No finish is forever.
I use an epoxy with a UV inhibitor for anything going outside. I made a cedar picnic table 2 years ago and the epoxy has locked in the colors of the cedar and it hasn't turned grey and it still looks like the day I applied it.

 
Anything worth doing is worth doing well.

Offline Weekend_Sawyer

  • Senior Member x2
  • *****
  • Posts: 3860
  • Age: 61
  • Location: Laurel, MD
  • Gender: Male
  • Jack of all trades, master of fun
    • Share Post
Re: Epoxy theory....
« Reply #5 on: August 16, 2018, 07:57:01 AM »

 That is a very nice looking table.

Here is a tip, when you view your pictures in your gallery there is a crop and rotate button.

Jon
Imagine, Me a Tree Farmer.
Jon, Appalachian American Wannabe.

Offline samandothers

  • Senior Member x2
  • *****
  • Posts: 3779
  • Location: Charlotte NC To SW Va.
  • Gender: Male
  • Been learning on FF since 1/20/12
    • Share Post
Re: Epoxy theory....
« Reply #6 on: August 16, 2018, 10:57:37 AM »
This discussion is help full. I am looking to put someing on a wood top vanity.  Have considered epoxy.  Some others have suggested shellac or Waterlox.  Two of these I believe would encapsulate.  I believe the Waterlox would penetrate.

Decisions decisions.

Offline Don P

  • Senior Member x2
  • *****
  • Posts: 8769
  • Location: Southwestern VA
  • Gender: Male
    • Share Post
    • Calculator Index
Re: Epoxy theory....
« Reply #7 on: August 16, 2018, 05:43:14 PM »
All three are film forming finishes. Waterlox is basically thinned varnish.
The future is a foreign country, they will do things differently there - Simon Winchester


Share via delicious Share via digg Share via facebook Share via linkedin Share via pinterest Share via reddit Share via stumble Share via tumblr Share via twitter

xx
Best way to dry slabs??? Everyone seems to have a different theory

Started by Segerdog on Drying and Processing

37 Replies
1405 Views
Last post April 04, 2021, 07:55:44 PM
by doc henderson
moved
MOVED: Generational theory

Started by Roxie on General Board

0 Replies
483 Views
Last post February 10, 2017, 10:21:35 AM
by Roxie
xx
Grapple skidder theory?

Started by Satamax on Forestry and Logging

22 Replies
3273 Views
Last post September 11, 2018, 02:35:52 AM
by DDW_OR
xx
Epoxy

Started by Bill Gaiche on General Woodworking

22 Replies
2467 Views
Last post November 01, 2015, 05:23:22 PM
by Kbeitz
 


Powered by EzPortal