I want ideas to increase the penetration of oil finishes in cherry and walnut (& other) for two main reasons:

1. Increase the chatoyance / moire / shimmer / reflective depth in the wood.

2. Increase water resistance due to more finish resin deeply impregnated into the wood.

I'm not a newbie to oil finishes - we have done hand-rubbed oil finishes exclusively for 20 years - probably $10M plus product in the field - very high-end flooring, doors, wainscoting, cabinetry, ceilings and furniture. We use polymerized tung oil and a linseed oil based UV cured oil. We've used D-limonene (citrus oil) as the thinner. I have a pine BT vanity in my house on which I used above finishes and in 5 yrs have never had water rings even though people in the house don't wipe up (as I do!!) under the liquid soap bottle or splashes from the sink. Also an elm dining table top that never rings up - though the table top I wipe on a couple coats of PTO (Polymerized Tung Oil) at least once a year as daily wipe downs with dishrag seem to strip the finish a bit.

I'm looking for ideas to increase penetration and increase the pluses of #1 and #2 above - ideas?

I've heard that heating the oil (linseed) does not really increase penetration but my own quick tests were inconclusive.

1. Solvent and technique ideas?

2. Crazy idea - would putting the wet boards in a pressure chamber for a few minutes help penetration? Anyone actually tested this?

3. Crazier idea - would putting the wet boards in a vacuum chamber for a few minutes help? Anyone tested this?

For this thread please keep all responses related to OIL finish penetration and do NOT talk about comparisons with other finishes.

Thanks!

Viagra?

I would first look at how much value the extra work would add and whether the end user would be willing to pay it.

You are talking about pushing the product deeper into the pores if the wood. This would require either a lower surface tension or viscosity, adding pressure through force or vacuum as well.

Essentially you are trying to displace the air in the pores with a liquid so you also need the air in the pores to have a place to go.

How much additional penetration are you looking to achieve? Just a little or to completely fill the pores?

Multiple applications of the oil finish as follows: First coat should be flooded into the wood, wait thirty minutes, remove excess with lint free T shirt material. Let dry for 24 hours. Then the process starts.
Second coat, flood the oil onto the surface of the wood, begin wet sanding with 200 grit Wet/Dry Sandpaper. I use a festool orbital with no vacuum. Thoroughly sand the entire area. Let the slurry sit on the surface for 10 to 15 minutes, then remove the excess oil. Wait 24 hours. Next step is begun with 400 grit. Same procedure as above. Wait 24 hours. Next step is with 800 grit. After that, proceed with 1000 grit, followed by 1200, then 1500 and then 2000. Always wait 24 hours between wet sanding. The wood pores will be totally filled and a mirror finish will appear.

The end result is a pretty nice. But it will take you about two weeks to achieve

A vacuum is going to draw air out of the wood, so it will bring all the oil to the surface. Not what you want. On small work, I use the heal of my hand to build up some heat while the oil is on the surface. I haven't applied an oil finish in decades. Just couldn't make money taking that long to apply a finish. Customers could care less is my opinion. What if I WANT to talk about other finishes? What happens?

Your best bet is to immerse them in the finish for as long as it takes for the wood to absorb the amount of oil you are looking for.

I would imagine a tank big enough to fit your largest pieces would be the easiest way to do the job.

Scott, I have a question, am I clear to understand you are curing the oil you use under UV lamps?
Couple things, yes soaking it in a big vat would work, way back in the day a company called "The Bare Woods" in SanDiego stained everything this way.
But, Very oily wood and glue joints may not hold up over time. I have had glue joints let go on maple dining tables from people that are heavy lemon oil users.
Vacuum Chamber will work, Pull a heavy vacuum and then inject oil under vacuum. Better have a big check book for that option.
I think you need to reformulate your product, but if you UV cure the deeply penetrated oil may not crosslink also.
Lots to think about.

Why not just use a water based stain. It will naturally want to soak in deep.

It is the oil I am trying to get in deeper, not so much the color - we successfully dye after the first couple oil coats on cherry (no blotching ever). So let's assume for this thread that all we are doing is oils only - no colorants. I want to deepen the reflectivity of the wood and get more moisture protection.

I have a small Pizzi glue pot, I think I will do an experiment with a board cut in half and put one piece in the pressure pot wet with oil then take out and wipe after 5-10 min, and the other let soak at atmospheric pressure for same time then wipe both and compare after curing.

I am also concerned about the soaked in oil curing adequately as UV may not reach in as far as the oil penetration. more experiments...

I do wonder about thinning and/or heating the UV oil as well.

Does anyone know a green natural thinner that is faster evaporating than D-limonene (citrus peel oil)?

10M dollars in the field, I can't think of a poorer choice, for what you call high-end millwork. I would love to go on, just about the cost to apply, but I will not.

Technical answers related to penetration of oil finishes --- Please keep responses related to the thread - other issues start another thread if you like. tks!

Can't teach an old dog a new trick or you can lead a horse to water but can't make him drink.... I'm flabbergasted at the way people buy in to things like this is the magic way to do things.... Oil finishes can have their place but where we are today with how finishes have been developed in this century why not use a product that offers clarity.. flexibility.. moisture resistance, mar resistance, uv inhibitors and many other characteristics that these great engineers have developed in film coating technology... all wrapped up in an easy to use package... you can still have close to the wood finishes these days with superior protection.. I just don't understand why people slave hours over oil... where it takes weeks to finish something? and then stand back in awe like they did something.... Wow. shoot the dang thing with two coats of a superior product today and build your next project... labor is expensive

Pls stay on topic - start another thread if you like and i'd be happy to discuss why we do it for our traditional hand-planed aged products that go into multi-million dollar homes.

You crack me up Scott, thanks for the laugh!

I don't get why you would use a UV curing system if you're trying to allow the finish to penetrate deeper. It would seem time is your friend. IMHO chatoyance is based on having a lens (hard coating) to look into the wood. A super tight finish to me would be the opposite as the light gets soaked up by wood grain.

my2cts

Scott,

Please feel free to respond to me as if I am the village idiot.

All of the penetrating oil finishes that I have used all penetrate quite deep. It reads like there are no durability issues based upon your own at home experience.

Therefore you are really looking to change the look of your finish. Increasing the depth will not do that beyond what you've already got. You can't see deeper than just beyond the surface.

I would focus more on a different product of the same type or the sheen of the existing product.

Scott,
I'm a little bit confused about how you use chatoyance, i.e. the rippling, cats-eye effect. You seem to imply that allowing an oil finish to penetrate deeper will increase the chatoyance.
My understanding of chatoyance (and I've a very strong background in materials science as well as wood technology), is that the primary cause is cross-linking of wood fibers (or stone for that matter). Adding oil will definitely highlight the existing chatoyance; so will a very light stain; which is a very common treatment for both curly and birdseye maples. Your diligence in adding the oil must clearly bring out the existing chatoyance, but I cannot see how adding more oil can increase it, since the root cause comes from the fibers, not the finish.

Scott - your hypothesis that increasing the penetration of a drying oil will improve reflectivity/chatoyance/shimmer and water resistance is wrong.

The properties of various finishes, including drying oils, is well documented and can be found with just a little research. Look for moisture excluding effectiveness - MEE. Drying oils are at the bottom of the performance list.

Any finish that provides good clarity will bring out the directionality in the wood grain. The article I'm attaching explains the cause and effect well. To enhance the effect, you can use dyes, glazes, and toners.

Click the link below to download the file included with this post.

Directional_Reflection_in_Figured_Wood.pdf

Allan
You may be quite right - we might already have maximized bringing out the inherent chatoyance of the wood. My assumption, which may be wrong, is that I might be able to bring out more with deeper oil penetration which will allow the light to go in and reflect out deeper - sort of like how putting oil on a sheet of white paper greatly increases the amount of light that can pass thru. Or another way to put it that might awaken more readers - sort of like the difference that a bucket of water makes on a dry white t-shirt on a beautiful young woman without anything on under the t-shirt... the water brings out the inherent color and beauty that is within. To tie this back to an oil finish - a top coat of finish on the t-shirt will not help, it is the liquid IN the fabric down to the skin that allows the light to penetrate and reflect the color and beauty back out.

I think the reason the pine vanity top in my bathroom has done so well is that the pine, being soft, soaked up a lot more oil than a hardwood. That hardened oil is what gives the water resistance. I'm hoping if I can increase the penetration on hardwood that I can increase the water resistance and still have the close-to-the-wood look and feel rather than having it look like it's been dipped in plastic.

Have you tried spraying your oil? Maybe a high pressure spray gun would help.

Nice work Todd. Must be nice shooting
clears all the time :-). I'm currently in a pigmented finish streak of 5 jobs in a row. Pays more for sure but.......I could do without Bondo and caulking for awhile.

cheers

Very very beautiful work Todd.

Are you shooting oils or something else?

Scott,
I believe the reason that you achieved superior results adding more oil to pine is simply a function of density, i.e. the wood fibers are not as densely packed. Adding more oil makes sense for pine. For hard maple, rosewood, or even walnut or cherry, I doubt that additional oil will penetrate much beyond what initial soakings provided.

In the old times, one of the best penetrating sealers for terra cotta Mexican Pavers was a mixture of one part Linseed oil and two parts Turpentine. It penetrated deep as the solution was more fluid. The problem was that any leftover rags would easily catch on fire (spontaneously!), so the practice was stopped.
For best penetration, the wood should be dry. Dilute the oil with turpentine (use Raw Linseed instead of Boiled), the diluted mixture would give you a slight increase in penetration (for obvious reasons).
Heating the mixture would also add to the penetration power, but be careful as the mixture is combustible.
For best seal (via oils) the wood should be oiled, with the above mixture, daily, for the first week, then weekly, for the first month, and then monthly, for the first year :)

While the maximum pressure differential via vacuum is one atmosphere (15psi), it is effective. A wetted or submersed piece of clear fir as an example takes up a mixture of heated 1:1:3 (bees wax:linseed:tung) oil at a depth of 0.125 inches, in just a few minutes. For production scale a retort is a good choice as it can be heated and presurized. I use a bag to keep the liquid on the surface, then put on a vacuum spreader (a mesh to keep the bag off the surface of the wood), I heat the system enough to ensure the bees wax stays in solution. I put the tube that comes out of the bag out through the bulkhead fitting in the side of the chamber and pull a vacuum with a scroll pump. I also pressuize the retort to increase heat conduction to the part(s) in the bag 7-12 psi is plenty. Cycle to full vacuum (about 1mm hg on the vacuum gauge). This pulls the air and other volatiles out of the wood, including organic acids. I use a trap containing a base to scrub acids befor they get to my vacuum pump. If the surface is wet with oil mixture, when you release the vacuum the oil will rush back into voids in the wood, filling them with oil. If you need help give me a buzz at 206 643 5040. No charge for advice:)