LumberJocks

Soaking End Grain in Polyurethane

  • Advertise with us

« back to Finishing forum

Forum topic by MikeyPiano posted 02-02-2021 02:10 AM 1138 views 0 times favorited 26 replies Add to Favorites Watch
View MikeyPiano's profile

MikeyPiano

32 posts in 240 days


02-02-2021 02:10 AM

Topic tags/keywords: end-grain polyurethane soak

I decided to try soaking the end-grain on some kitchen table feet. I’m happy with the way it’s drinking up the polyurethane. This is what it looks like after 1-2 minutes. Do you think that’s all I’ll need to do for the bottom end-grain or is there another step I should take? This table will be used outdoors, under a BBQ pavilion.

notes:
- legs are 1.5×1.5 inches
- there’s a light chamfer on the feet
- soup lids from Chinese take-out


26 replies so far

View Lazyman's profile

Lazyman

6986 posts in 2468 days


#1 posted 02-02-2021 03:01 AM

My guess is that the wood is absorbing mostly the oil base and less of the resin.

What is your goal in doing this?

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

View woodbutcherbynight's profile

woodbutcherbynight

9176 posts in 3490 days


#2 posted 02-02-2021 03:14 AM



My guess is that the wood is absorbing mostly the oil base and less of the resin.

What is your goal in doing this?

- Lazyman

I wonder same thing. For outside work such as this I use clear caulk or silicone and let cure for a week. Seals the ends up and gives a measure of protection from wicking of water up into the wood.

-- Live to tell the stories, they sound better that way.

View bigblockyeti's profile

bigblockyeti

7255 posts in 2801 days


#3 posted 02-02-2021 11:53 AM

I would be inclined to install plastic nail on feet to keep from abrading away any film finish on the end grain when it’s slid across the ground and to elevate it from even the slightest water to avoid wicking any up.

-- "Lack of effort will result in failure with amazing predictability" - Me

View John Smith's profile

John Smith

2924 posts in 1243 days


#4 posted 02-02-2021 12:38 PM

that is probably 99% more than most of us do for interior projects.

-- there is no educational alternative to having a front row seat in the School of Hard Knocks. --

View MikeyPiano's profile

MikeyPiano

32 posts in 240 days


#5 posted 02-02-2021 01:23 PM


My guess is that the wood is absorbing mostly the oil base and less of the resin. What is your goal in doing this?
- Lazyman
That’s interesting about the oil vs. resin, I’ll check to see what happens. My goal is to protect the feet from wicking up water.

The table will be in hot humid weather all year round. It might also get dragged around and occasionally placed on wet grass/dirt/concrete.

View MikeyPiano's profile

MikeyPiano

32 posts in 240 days


#6 posted 02-02-2021 01:27 PM

For outside work such as this I use clear caulk or silicone and let cure for a week. Seals the ends up and gives a measure of protection from wicking of water up into the wood. – woodbutcherbynight
Thanks for the tip, I’ll look into the caulk and silicone. What are the benefits over polyurethane?

View MikeyPiano's profile

MikeyPiano

32 posts in 240 days


#7 posted 02-02-2021 01:29 PM

I would be inclined to install plastic nail on feet … – bigblockyeti
Definitely, nail on feet after the polyurethane is dry.

View AlanWS's profile

AlanWS

136 posts in 4639 days


#8 posted 02-02-2021 01:30 PM

That should help to protect the feet from moisture. As noted above, the usual approach is to attach a foot to keep the wood off wet surfaces. I have used very thin epoxy that soaks in and hardens without any need for evaporation (System Three rotfix) and it has worked well for years outside.

-- Alan in Wisconsin

View Lazyman's profile

Lazyman

6986 posts in 2468 days


#9 posted 02-02-2021 02:39 PM

One problem with putting any film finish on outdoor furniture it that it will eventually crack. When that happens water will seep in and ultimately get trapped under the finish which will cause it to mildew. If it is protected from sun and rain it will take longer for that to happen but it will eventually happen. Refinishing an old cracked film finish usually requires you to strip the old finish. IMO, It will actually do better to have a non-resin exterior oil based finish that can breath so that any water that does get absorbed will dry quickly but you will have to refresh the finish fairly often depending upon how exposed to the elements it is. An oil finish can usually be refreshed with light scuff sanding and a fresh coat. If the table will usually be sitting on a hard surface and just occasionally sitting on soil, I would not worry too much about the legs but some feet or end caps would not hurt.

If you do opt for something like a poly finish, make sure that you pick one that is a spar finish. They are usually more flexible and will resist cracking longer.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

View DS's profile

DS

3746 posts in 3501 days


#10 posted 02-02-2021 03:09 PM

Why not add adjustable glide feet to the bottom to keep it level and off the ground?

-- "Hard work is not defined by the difficulty of the task as much as a person's desire to perform it.", DS251

View SMP's profile

SMP

3968 posts in 986 days


#11 posted 02-02-2021 03:23 PM

I second what DS posted. As pretty much no surface, outside especially, is flat. Plus keeping the bottoms from dry rotting.

View newwoodbutcher's profile

newwoodbutcher

861 posts in 3931 days


#12 posted 02-03-2021 05:43 AM

I’m no expert but I think sealing the bottom of an outside wooden leg will lead to faster wood rot by holding water in the leg instead of letting it drain.

-- Ken

View Kelly's profile

Kelly

3547 posts in 4025 days


#13 posted 02-03-2021 06:17 AM

I think it’s an excellent ideal. I did this off and over the last forty years, but thinned the poly as much as 30% or so.

Since items I did this with sat in front of a well used wood burning stove, for several decades, without cracking and splitting from moisture loss, it should be obvious the items didn’t gain much moisture either.

The poly was so penetrating one six inch slab, a gallon in, started showing wet spots on the bottom, which were discovered only when I dropped my brush and bent down to pick it up. AND, if it was only the oil penetrating, the top would have been clear coated with resin. It wasn’t.

I love penetrating coats without built up surface coats. I’ve never had one crack, like I have surface coats.

If you were concerned about wood shifts with moisture gain and loss, bend the poly formula with some more hardening oil, to bring it more to a long oil finish, which is what is used for nautical finishes. Long oil finishes are less durable, but more flexible.

I do not believe this method would, in any way, speed rot. This is nothing like burying a post in the ground and surrounding it with concrete [which holds moisture in]. It is like what I do with plywood and particle board counter top bases around a sink, to stop unintended moisture contact from penetrating.

ALL the above aside, when I build steps and things, I slip a piece of granite tile under the 2x’s to minimize contact with the sidewalk or ground. In that vein, what DS suggested would be a good idea.

View MikeyPiano's profile

MikeyPiano

32 posts in 240 days


#14 posted 02-03-2021 07:22 AM

UPDATE #1
Here’s what the feet look like after soaking in polyurethane. I’m satisfied with this, mainly because it’s basically labor free (what a bargain!). Just let it soak overnight and by morning it’s penetrated the end-grain and there’s a thick coat to boot – better than I would have gotten doing it by hand. I’ll sand it down and manually poly the rest of the wood. Nail-on-feet are coming in the mail. FYI – regarding the end-grain soaking up the oil vs. the resin – the end-grain sucked up 90-95% of the poly I put in those plastic covers, so hopefully that’s a good sign.

UPDATE #2
I checked into the silicone caulk vs. polyurethane. Apparently, silicone is very effective on most other materials – except wood and paint (which is I guess where polyurethane comes in). Also most silicone caulk works better in warm weather, while special forumulations are needed when it’s colder.

View becikeja's profile

becikeja

1172 posts in 3894 days


#15 posted 02-03-2021 10:47 AM

I recall an episode of the wood whisperer where he coated the bottom of outdoor furniture legs with epoxy. Have never tried it myself.
Unfortunately only time will tell how this works out.

-- Don't outsmart your common sense

showing 1 through 15 of 26 replies

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com