17 July 2019 at 11:27 am #590714
This is my first post. I am very inexperienced and would much appreciate some guidance please. I am about to make an external door using oak which has sapwood which I cannot cut out without the board being too small.
Am I safe to proceed and if so should I treat the finished door so that the sapwood and the heartwood remain the same colour? Advice on how to do this would also be greatly appreciated!
Jae18 July 2019 at 8:06 pm #59123119 July 2019 at 1:32 pm #59143119 July 2019 at 2:12 pm #591450
Thanks for posting that. I wanted to make sure that we’re just talking about sapwood and heartwood and not a piece that included the pith. There’s no pith here, so that worry is gone.
I have not made architectural doors nor outdoor furniture and hope someone else can answer those aspects of your question. For my oak projects, I select just by appearance of the wood and lay out the color and grain patterns by esthetics. Unfortunately, variations in color are hard to avoid, so the pieces I’ve made have had color added when finishing to even things out. That isn’t always needed, depending upon your tastes.19 July 2019 at 9:46 pm #591604
Many thanks for taking the trouble to look into this for me. I am sure that I will be applying some form of stain. I don’t have enough wood to avoid the sapwood. My father’s favourite saying, as he got older, was “it will see me out” and he was right (I come from a farming family). Trouble is we are now doing what was deferred and have been at it 12 years!
Jae20 July 2019 at 1:51 am #591659Sven-Olof JanssonParticipant
My two pennies worth of thoughts on doors, based on some experience from making them.
Indoors or outdoors, doors (couldn’t resist) are prone to warp. I imagine it’s because of differences in temperature and humidity between their lower and upper parts. For an external door this means that it is important to provide some form of coverage against rain, above the door. If that can be sufficiently extended to also protect the lower parts of it against downpours, then so much better; though, of course, that isn’t the general case.
Oak is very resistant against the effects of moisture, and will – similar to other wood species – as long as it can dry up between becoming wet, last for a very long time, though perhaps not aesthetically pleasing (see attached photo of an oak pier).
As sapwood is more susceptible to rot, it can be a good idea to have it at the upper parts of an external door, where it is less exposed moisture.
Having left two external doors without any coating, I’ve learnt that they swell and become ugly, and that’s not good even if they last. Consequently, I nowadays use polyurethane varnish to protect their looks and function.
The attached link is to a page that discusses finishes for outdoor projects.
Best of luck
London, UK; Boston, MA28 July 2019 at 11:16 pm #594202Johan TidelandParticipant
I will give you my view on the matter from my perspective.
I am an apprentice in wooden boat building and before my apprenticeship I was 2 years in a wooden boat building school.
In boat building oak is considered to be very good, it is strong, rot resistant and is easy to steam bend.
However the sapwood is A LOT more prone to rot, much less stable, generally soft and it is not unusual that parts of it just pulverizes if you poke around in it. Therefore no sapwood of oak whatsoever is allowed in a boat.
From the 2 pictures of the end grain it looks like they consist of about 80% sapwood.
I am not a joiner or cabinet maker and thus do not have any experience in making doors for houses but if I had that material you showed I would certainly not use it for anything outside, in fact it would most likely end up in my firewood pile.
Sorry if I spoil it for you, good luck tho, I hope you can get some other better pieces
Just my 2 cents29 July 2019 at 7:22 am #594292
The pictures you showed are a bit rough in texture, making harder to determine if your oak is in the white or red oak families. Red oak is ring porous and absorbs water easily, making it not so rot resistant. White oak is quite rot and weather resistant. Two ways to tell are to plane the ends of the wood Red oak will have obvious open pores)you can actually take a sprig of the wood and blow through it into a glass of water. With red oak you can blow bubbles.
A boat has a lot more water contact than a door. Properly protected and finished six sides, some sapwood is acceptable if you can make the colors match. If the door has been there years with no finish and is still sound, you are probably fine. Consider yourself lucky.
As to reestablishing the color, I’d first wash the oak door with an oxalic acid wash to bleach the wood even. Then try a water based dye stain followed by a light sanding, The water based stain can be controlled by thinning or applying more to get the light and dark oaks more the same. Follow with a sanding sealer ( 1/2 pound mix of shellac will do, followed by a sanding to knock back the fuzz from the water based stain ( sand most of the sealer off but not the stain) and finally a oil gel stain topcoat. Wipe that off after a couple minutes. How long you leave it on matters a lot.
I’ve had good luck with General finishes products. They seem predictable.
You can always stain darker. You can’t stain lighter. I then follow with a couple coats of thinned shellac, followed by 0000 steel wool to get the surface smooth. If you use amber shellac or darker ( thinned) you can sometimes even out the color. Stop before the grain gets muddy. If you get too dark or don’t like the effect, you can wipe the dark shellac off with alcohol. This is your second shot at experimenting.
For a final finish I’d use a spar varnish, NOT a poly varnish. Most poly varnish has no UV inhibitors that protect the finish, and poly varnish isn’t renewable with a simple light cleaning and new coat. Poly doesn’t stick to hard poly very well. You will eventually get flaking and have to strip and start over.
Spar varnish, on the other hand, does offer UV protection and is renewable with a OOOO steel wool going over followed by a fresh coat. Get a marine spar varnish, not the box store kind. ( Interlux, or my favorite, Epifanes) It’s frightfully expensive but has much higher solids content. For a door, I figure a pint per coat. $20-$30 per pint. Thin as directed at least 3 coats. Lightly sand between coats. Get into the zen of it.
It will probably be too glossy. When thoroughly dry, wax with OOOO steel wool to knock the sheen back. Stand back and admire. And I’ve found that if the finish is sound, you can make a wiping varnish to renew the sheen and hide scratches on a sheltered door. Wipe off the wax with mineral spirits first. I use 50-50 walnut oil and varnish. A very thin coat is enough. That only takes a few minutes and dries in a couple hours. Mind the weatherstripping doesn’t contact a sticky door.29 July 2019 at 1:31 pm #594346
You said you are a beginner, so I’d like to try to simplify and clarify things for you. First, it is good that you are thinking about the reality of the wood and learning about it, e.g., sapwood vs. heartwood, but my suggestion is to just build the door as long as the wood seems strong right now. If you need to rebuild the door in the future, so be it. You’ll have more experience then, but right now you are in danger of getting bogged down in details and not getting started. So, just go ahead and see how things go.
With regard to finishing, I do something like what @lorenzojose describes for interior furniture, but with far fewer steps / layers. I apply General Finishes dye stain for color, then wipe a coat of their Arm-R-Seal, which is oil based, and then apply their water based topcoat (High Performance). The reason for the oil based Arm-R-Seal is that, since I am not always spraying, it locks down the water based dye and keeps it from being picked up by the water based topcoat. Really, though, I could just keep going with the Arm-R-Seal, but it runs easily and requires more time to dry between coats. Also, it is for indoor use.
If you are doing something fairly simple, like a door, I think you could skip the razamataz of so many different coats and just go from water based dye stain or General Finishes stain to a water based topcoat. Just don’t work the first coat of topcoat. “Put it and leave it.” I don’t know how good the General Finishes Enduro 450 is (a water based exterior topcoat), but if you find it acceptable, then a simplified finishing schedule is to just apply the general finishes dye stain or stain, let it dry overnight, and then move on to the Enduro 450. No oxalic acid, no shellac, no sanding sealer. You’d only need the oxalic acid if you want to end up with a light color. If you are happy darkening everything to be something like the darker heartwood, or a bit darker, you can skip it. I understand why Larry wants to use it, but for a beginner on a first project, it’s an extra step and a non-trivial one.
So, those are the simplifications. Here are some clarifications:
1. It is okay to put oil over water, but things must be dry, dry, dry. Give the water based coat at least 24 hours to dry. I routinely put oil over water with General Finishes and know they are compatible. If you use other brands or mix brands, you’ll need to test.
2. It is also okay to put water over oil, but the oil must dry at least 72 hours before applying the water based coat on top. I’ve had cases where I needed to wait much, much, much longer. It is important to note that “oil based” means something like Arm-R-Seal, i.e., a varnish with drying agents, and does not mean BLO or other true oil. Again, general finishes stuff is compatible between water and oil in my experience. If you sense any tackiness or strong odor, it needs to dry more. Resinous wood, like pine, can give trouble here.
3. I will disagree with Larry in one detail. Do not try to remove the fuzz after you put on the water based dye. Unless you are super skilled, you will almost certainly sand through your color. Ignore the fuzz after putting on the dye stain or stain. Get your first coat of finish on over the dye or stain and then give *one* wipe with 600 grit. I like the foam backed Rhynosoft pads. It’s not sanding…just one wipe. Stay away from corners, mouldings, etc. This will remove about 1/3 of the fuzz. Ignore the rest, stifle the worries that you are ruining the project, and put on your second coat. After the second coat, again wipe with 600. You can be more aggressive now *if* you are using a water based finish because you have some finish down, although it is easy to sand through corners. If you are using oils that go on with thinner coats, continue to take great care and continue with light wipes between coats. Continue like this to build your film.
I think you will find this approach to fuzz much more feasible. You simply must have something to sand and, after dye, there’s nothing to sand. There’s not enough binder in it. What I’m describing is a mixture of just burying the fuzz in the finish, where it disappears, and progressively removing it as you build up the finish coats. With the General Finishes products, at least, you do not need the sanding sealer. The sanding will be easy enough if done as I described. You don’t need sealers. The finish is the sealer.
Hope this helps. If you want to go even simpler, pick out a General Finishes water based STAIN (rather than dye), wipe it on, wipe off the excess, let it dry. Then, start applying Enduro 450, but research whether it is okay. I know one person that uses it, but I’ve not used it myself. Larry has a lot of experience, so if his favorite spar varnish is compatible directly over the GF dye stain or the GF stain, that’s probably a great option. Larry, why the gel topcoat *and* spar varnish? Were you thinking a colored gel coat and it was for toning/glazing?
Whatever you decide, test the finishing on scrap.
We didn’t need to talk about blotching because you are using oak. That’s a good thing.
Ever considered a glass storm door?29 July 2019 at 9:46 pm #594462SelvaParticipant
@ed: regarding “Enduro 450”, the only GF topcoat listed as for exterior use I could find was “exterior 450”. I’m considering the exterior 450 for some patio furniture as its locally available, though its rated only for “for vertical surfaces”. If there is an exterior varnish in the Enduro line that could be an alternative.
29 July 2019 at 9:56 pm #594464
- This reply was modified 3 months, 3 weeks ago by Selva.
@selva good catch! Yes, I meant Exterior 450. Thank you.
If Larry tells us his favorite spar varnish is compatible with GF dyes and water based stains without the need for the gel (and maybe even with), I’m going to write that down for the future reference. I think that means Epifanes Clear and Interlux.30 July 2019 at 1:13 am #594501
Larry, why the gel topcoat *and* spar varnish? Were you thinking a colored gel coat and it was for toning/glazing?
Yeah, I was thinking the colored gel stains. I just think you get better color and tone control by separating the steps. I use the dye stain to even out the tonal value between the sapwood and the heartwood. I use the gel stain more for hue.
I was mainly addressing what to do if parts of what you are trying to finish are wildly different. Obviously, if all the wood is one piece or very uniform, everything gets a lot easier. Then just stain with what you like and Carry on.
With both the dye stain and the gel stain you can control the tone and hue on different parts of a piece by changing the strength and number of coats. Water down the dye stain on parts that are already dark and go full strength on the light parts. Then blend them with a slightly damp rag.
Putting a light sealer between the steps evens out the effect of the gel stain without getting the result all muddy.
As to the sanding after the water based dye stain, just dye it again if you break through the dye layer. the fuzz won’t raise much the second time. You can even control the tone by doing it carefully.
On blotchy wood like beech or maple it sometimes helps to put a sanding sealer on first and sand that almost completely off before staining. It fills the areas that normally sponge up stain
It puts you more in control. You aren’t just at the mercy of whatever a single coat of stain wants to do. I’m almost never completely happy with that. I seldom want the whole piece to be the color of the darkest wood. I generally try to just get it so all the parts work together and you still see the grain.
The spar varnish has good U.V. inhibitors in it, which has so far pevented the dye stain from bleaching out over time on projects I have done, which I used to have issues with. I also think newer dye stains are better in that respect. I’d never depend on any clear finish that didn’t protect what you did underneath.
This piece was even in tone 50 years ago, but over time the dye stain bleached. The goal in refinishing was to get the parts to blend without making the piece too dark. Excuse the blurry before photo, but it shows the original color variance the best.30 July 2019 at 1:37 am #594505
If Larry tells us his favorite spar varnish is compatible with GF dyes and water based stains without the need for the gel (and maybe even with), I’m going to write that down for the future reference. I think that means Epifanes Clear and Interlux.
Yah, those are the spar varnishes I use. I put a coat of shellac down as a sanding sealer before the varnish. If you ever have a compatibility doubt, just put a coat or two of clear shellac down first. The old saw that shellac sticks to everything and everything sticks to shellac holds true with everything but poly in my experience. And it’s a quick ( and cheap) way to build up a finish. I lightly Sand with 320-400 grit open core between te shellac and the varnish and between coats of varnish.
30 July 2019 at 2:09 am #594508
- This reply was modified 3 months, 3 weeks ago by Larry Geib.
Have you ever tried to put those particular spar varnishes directly over the dye without the shellac barrier coat? For my purposes, skipping the shellac is important, so I’m curious about direct compatibility.30 July 2019 at 9:00 am #594538
No. Honestly, I’ve never used the water based dye stain by itself. But there shouldn’t be any problem. Epifanes is just a traditional varnish except with more solids. There is no weird chemistry or solvents. It’s tung oil, modified alkyd resins, and the U.V. inhibitor.
Just make sure the work is dry. And if it’s an oily wood, degrease with mineral spirits or isopropyl alcohol.
If you have tried any other traditional varnish and it worked, I don’t see any reason Epifanes wouldn’t work.
Here are the Epifanes directions and compatibility statements, which I see haven’t changed much.
I do notice that GF talks about using water based topcoats. I don’t know if there is a real reason. They do say you can use oil based gel stain over it.
Just for grins, I put some dye stain on a fir scrap and gave it a quick blow dry. Then I put some alkyd varnish on it full strength. I’ll let you know in the morning how that went.
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