Bag of joint compound is staring me in the face - filling red oak

[Todd Burch]

I don't work with red oak that much, but I've just made a counter top for a living room built-in (call it an entertainment center) out of red oak ply, and also two face frames for a couple bedroom built-ins. The red oak bullnose stock will be delivered in the AM for the counter top. The doors for the bedroom built-ins will arrive in a bout a week. I still need to make the red oak drawer fronts.

I went to a local Sherwin Williams for assistance with filling the pores, and, to make a long story short, I left the store in a huff as the guy waiting on me didn't know ship from Shine Ola and was quite condescending. "Why in the world would I want to fill the pores in red oak?" he asked. "Why don't you just stain it and spray it - that will fill the pores". Idiot.

I want to fill the pores on this red oak, but I don't want to spend a lot of time doing it. I'm considering mixing a wet batch of joint compound and troweling it on and sanding the top of it off after it dries. My plan is to use an oil based stain and then spray lacquer on both items. I'm OK with the pores being darker than the wood.

Would this work? Pros? Cons? Any better or faster ideas?

Thanks, Todd

[Jason Roehl]

Test it on a scrap, but I don't think you'll like the results. I've seen stain get on raw joint compound, and it definitely absorbs it much more than the wood, but I wasn't really looking at it with an eye towards finish.

Here's something that you could use:

http://www.amazon.com/Woodwise-14-lb...ed+wood+filler

http://www.woodwise.com/woodfiller/woodpatch-prop.html

A local hardwood flooring supply company may have it or something similar.

[Todd Burch]

Thanks Jason. Good idea. I just ordered a bag. I'll post back after I use to report results.

Todd

[Bob Wingard]

Joint compound is all I ever use when I do use a filler. An old timer demonstrated it at a WW show many years ago, and his samples looked fabulous. If you go that route, be sure to get a "setting" type of compound ... the kind that you have to mix water + dry powder ... it won't shrink, and it dries faster & harder. With this method, you have LOTS of flexibility as to color & contrast ... the compound can be tinted to match or contrast with the host material for a wide variety of effects. You can accentuate the pores lighter/darker, or even use a different color altogether for effect ... a spit coat of shellac over the base coat will keep the colors from bleeding into each other. Overall, it's a great choice ... look closely at the labels on commercial fillers ... ground silica in a base of some sort ... very expensive finely ground SAND !!!

[Ethan Melad]

I haven't used either of these specific products, but it seems to me that using something specifically designed to fill grain and make a smooth surface to finish would be your best bet:

http://www.targetcoatings.com/produc...r-a-glaze.html
http://www.paintdocs.com/docs/webPDF...5010549&lang=2

[glenn bradley]

I have used plaster of paris to fill red oak. It sands easily, becomes translucent with the application of an oil finish and takes a seal coat without problems.

[David Hawxhurst]

i've taken to using epoxy for pore filling of late.

[Todd Burch]

David, that's an expensive route to take - filling with epoxy.

Test Results

I received the wood filler Jason referenced above. The directions are primarily directed towards the floor finishing industry. Both joint compound and this wood filler warn of silica when sanding.

I used a piece of red oak ply - part of the cut-off for my counter top. On one side, I slathered up with "easy sand 45" setting joint compound. On the other side (after the joint compound fully dried) I mixed up a small batch of the wood filler. It's fairly yellow in color, even in powder form, and when mixed with a just a bit of water, it came to a warm peanut butter consistency (by "warm" I mean warm peanut butter is easier to spread than cold peanut butter) pretty quickly. I let it cure. Drying time for the wood filler might have been a bit longer than the joint compound, but I didn't stop-watch either of them. On both sides, I applied one end with a full cover coat, and on the other end, I knifed-off the majority of the paste. I did this to see if leaving a heavy coat versus a lighter coat would make a difference in fill characteristics.

Sanding

When all was cured, I got the Festool 150/3 random orbit sander with 180 Rubin and went to town. The joint compound took <60 seconds to sand out. Very fast. The wood filler took double or triple that, telling me that it was a much harder set than the "easy sand" joint compound.

The joint compound was (obviously) very white in color, and the coloring left after sanding told me I had left quite a bit in the pores. My initial impression was "mission accomplished". But, the test was not over.

The wood filler was yellow in color, and was (obviously) a lot less noticeable in the red oak than the joint compound after sanding. Both sides felt good - but to callused hands… what does that mean? Not much.

I then applied Minwax Red Oak stain (sucks - but it's the color I need) to both sides of the sample.

Did they fill the pores?

In a raking light, with still-wet stain, the joint compound side seemed like it produced about an 80% fill rate, while the wood filler side seemed like it produced about a 98% fill rate. I was very satisfied with the wood filler. I immediately decided, based on that, that the wood filler was the better option for filling pores than with the joint compound I had.

A few hours later, after the stained dried up a bit, in a raking light, the joint compound side seemed like it dropped to about a 30% fill rate. Very disappointing. The wood filler side dropped to what seemed to be about a 85% fill rate. Still good, but certainly not a perfect "guaranteed to fill every pore in one pass" solution. I'll take 85%.

Heavy coat versus light coat

Didn't seem to make a difference. The lesson I took away from this was to knife off the excess while still wet, make your material go farther, and spend less time sanding.

Notes

As most of us know, red oak grain can very greatly. On my sample piece, the grain structure was different on either side. On the joint compound side, there was about 1/8" (or more) of late wood between the growth rings, which means overall, there was a higher proportion of late wood (no pores) than early wood (heavily ring porous). On the wood filler side of the ply, it had about 1/16" (or less) between the late and early wood, which translated into a much higher ratio of ring porous veneer on the wood filler side than the joint compound side. Even with a much higher ratio of pores on the wood filler wide, it still excelled over the joint compound.

Here are a few pictures of the test - and the counter top I'll be filling with the wood filler.

Joint Compound applied (heavy on the left, light on the right)

DSC_8008.jpg

Wood filler applied (heavy on the left, light on the right)

DSC_8007.jpg

Joint compound sanded

DSC_8010.jpg

Wood filler sanded

*DSC_8009.jpg

Red Oak ply countertop and 1.5" bullnose. (Note - on the picture on the left, there is a narrow piece of 1/4" plywood between the left wall and the left-end piece of the bullnose. This picture was taken right after I glued the bullnose on, and that piece of 1/4" ply was my "spring clamp" for that short piece, as I was not able to get the slot cutter close enough to add a spline there.

DSC_8005.jpg DSC_8006.jpg

I hope you find this useful.

Todd

[Chris Padilla]

I'm glad to see someone else's MFT is as buggered up as mine.

[Tim Janssen]

Thanks Todd for spending the time doing this experiment. I'm sure that I will benefit from this sometime in the future!
(I'll bookmark this post)

Tim

[Todd Burch]

The MFT is a great work table and work platform (as in, OK for me to stand on). I need to spend some time to learn how to leverage it more. When I was assembling face frames, I used the MFT clamps to holds the frames in place and to the table. I hadn't ever done that before.

clamps.jpg

When sanding face frames, I used the same (as above) stop and a clamp to hold the frames up on edge when I needed to sand the edges.

When I was screwing face frames together, if a rail or stile had some bow to it, I would use my Festool circular saw track clamp. I put the "L" hook end down through the hole, and then used the screw end (above the table) to hold the wood flat to the table. Not sure if it was intended to be used that way, but the holes have just enough clearance for the track clamps to fit down through the holes.

Tim, thank you very much.

Todd

[Todd Burch]

Here's a shot of me using the MFT as scaffolding (nailing in the last piece of trim). The two legs on the right were on steps (garage leading up to the kitchen), and rear legs had stacks of wood scraps under them. It wasn't parallel to the floor, but it was plenty sturdy.

last_piece_of_trim.jpg

[David Hawxhurst]

epoxy isn't really anymore than behlen pore-o-pac. both would seem expensive compared to plaster of paris or joint compound.

[Chris Padilla]

Todd,

I have a post around here where I actually used TWO MFTs as a clamp. Look into the Qwas brand of dogs and dog rails. Great stuff!!

[John Coloccia]

Just FYI...a standard and reliable finish schedule goes something like this:

1) prep the wood
2) stain
3) 1 or 2 wash coats of finish...lacquer, shellac...whatever. Seal the wood and the stain.
4) pore fill. These days, I prefer thinned TimberMate, but I've used everything from epoxy (ZPoxy Finishing Resin seems to be best), to pore filler, to tinted joint compound. It all works, but I think TimberMate is the fastest and I can usually fill in one pass. There's a technique to it, but it's easy.
5) sand...don't go through the wash coats. This isn't hard to do but it seems like it would be.
6) spray another coat of lacquer to seal the pore filler
7) apply the rest of your finish

I like to apply the wash coat the night before, and then pore fill in the morning.

Anyhow, that's just a basic finish schedule. The purpose of the wash coats is to protect the wood from staining from the pore filler, and then to protect the stain from sanding back the filler. The washcoat over the pore filler locks everything in place so you don't need to worry about anything lifting later on. If something's going to do something funny, it will do it now when it's still trivial to fix.