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Replies
Big Al, you only need to fill the open grain when you want a high gloss, mirror like finish on your work. This is a very delicate finish, can scratch easily and should be reserved for special things like a dining table or musical instument. It's not a good level of finish for ordinary, everyday items. It takes a lot of work and is best done with certain finishing materials. If it's something you want to try, do a lot of research along with a lot of practice.
I don't know why you would say
that it is a delicate finish. filling is not a finish, but a step in achieving a finish. there are numerous finishes that can be applied over a filler coat to achieve whatever that you want.
ron
Grain filling questioin
I've been using CrysaLac for some time and really like it. A bit pricey though, but I get much better results that any other I've used. Apply a spoon then spread it around and work it in the grain with an old credit credit card or plastic hotel key. Couple of sources are Highland Woodworking and Woodcraft.
Grain Filling Question
Thanks for the info. I did purchase Crysalac and I think I will give it a try. I understand you have to dye the wood first then fill the grain. I wish that were not the case but I will do what is suggested.
grain filling techniques
One book I read:
"Brightwork: The Art of Finishing Wood" (Rebecca J. Whitman)
suggested a technique that I've used with great success. This is for mahogany, and assumes you will use varnish. I don't know how well it would work with other finishes:
Once you get the surface sanded/scraped and ready for finishing, get some tung oil (a component of some varnishes) and 400 grit wet or dry paper. Put enough tung oil to allow you to flood an area about 1 square foot and rub it in with the 400. This will create a slurry that will fill the pores. Keep rubbing/sanding until the slurry gets stiff. Then wipe off the slurry with a rough cloth (like burlap).
You can repeat as many times as you like.
Move to the next area and repeat, being sure to overlap.
When the entire piece is done this way, it's ready for the finish.
Grain filling, for formal finishes of woods like mahogany and walnut isn't all that difficult. But, some methods work better than others.
First, I would strongly recommend against the slurry recommendation, especially with tung oil at least if pure tung oil is used. With pure tung oil, the slurry would take a VERY long time to cure and the filler would still be very soft. Better results might obtain from an oil/varnish mix, but still the method is limiting, pretty much assuring that you could only achieve the natural oil wood coloration with little emphasis of grain. A boring look. Once you had filled grain this way you could no longer get acceptable dye results, and trying to use this method after dying is also likely to cause problems since you would be sanding off the dyed wood to create the filler.
Crystalac is a waterborne filler. As such is dries very quickly, giving you little time to work, so that much of the excess filler on the surface would have to be sanded off. Bummer, and with much sanding you still have to be careful about sanding through the dyed wood. Yes, dying should be done first--on bare wood. The other problem with Crystalac is that it tends to shrink quite a bit when curing so that you might well need two applications, spaced a week or so apart, to really get a smooth surface.
Personally, I much prefer an oil based pore filler. The best, with least shrinkage, are those with large proportions of silex as the filler. The Sherwin Williams wood grain filler, and the OlWid Master pore filler both have relatively large amounts of Silex. (The filler in S-W is all Silex, but it is available only in gallons.) Another advantage of the Silex (silica) filler that it has a bit more translucence that other materials which include chalk, talc, or plaster of Paris.
A particular advantage of pore filler is that you can tint it using Japan colors, artist's oil paint, or UTC colors. A good practise is to tint it so that it ends up just a bit darker than the base color of the dyed wood. This adds a lot of depth and enhances grain. Other things are possible, with a different look by making the filler lighter, or a different color shade.
If you describe more specifically the look of the mahogany that you are after, there are a number of finishing schedules that can really enhance mahogany. Yes, these involve more steps, but in the end make the process more fool proof and controllable. It would also help to know whether you have true mahagany Swientenia species, or one of the substitutes now available.
s
Grain filling, for formal
SteveSchoene wrote:
"First, I would strongly recommend against the slurry recommendation, especially with tung oil at least if pure tung oil is used. With pure tung oil, the slurry would take a VERY long time to cure and the filler would still be very soft. Better results might obtain from an oil/varnish mix, but still the method is limiting, pretty much assuring that you could only achieve the natural oil wood coloration with little emphasis of grain. A boring look. Once you had filled grain this way you could no longer get acceptable dye results, and trying to use this method after dying is also likely to cause problems since you would be sanding off the dyed wood to create the filler."
Since you "recommend strongly" agains the procedure (have you ever tried it?), I will reply strongly.
First question:
Have you tried it? Are you speaking from experience or conjecture?
I suspect I did not explain the process clearly:
First off, you do not "let the slurry cure". After the slurry stiffens (maybe after 5-10 minutes of "sanding") you remove ALL of the slurry on the surface of the wood. The only slurry "left" is that which is in the pores. Thereby filling the pores.
Secondly you do not want it to cure rapidly. The purpose of the tung oil is that it provides a binding for the varnish you are going to then apply. This makes for a very long lasting finish. You can, if you wish, use varnish for this instead of the tung oil but the tung oil works quite well. And remember you use a tung oil based varnish for this procedure.
I've done it - have you?
You can see some results here:
http://home.comcast.net/~saville/Constset.htm
http://home.comcast.net/~saville/chiplog.htm
Remember: this was the procedure for a varnish finish on boat "brightwork" - it's subjected to water and sun and huge changes of temperature. it's a very tough finish - I've used it on the brightwork of my boat and it lasts for years with minimal touchup (although the boat was in a shelter for the Late Fall, Winter, and early Spring).
http://home.comcast.net/~saville/SBOATrestore.htm
Why would you say you can "no longer get acceptable dye results"? The only thing that's filled is the grain pores. Again, you rub off the surface vigoroursly with a rough cloth after the slurry has stiffened. You remove as much from the surface as you wish. Also, nothing stops you from sanding the surface again if you think the residue oil prevents dye penetration (if it does) - and the pores will still be filled.
What is the difference between the residue oil left on the surface from your system vs mine?
About the ONLY difference I see between Whitman's method and yours is that you use silex as the filler whereas she uses...wood. And Whitman's system allows for varnishing a while after pore filling and still getting a really solid connection.
It's worked for me.
experience or conjecture?
I take it that you did this once on your boat . you read this from an article and now you are an expert. how long did it take you. 2. how long did it actually take for the tung or varnish to really harden(one can more than likely still go and stick a thumbnail into it and see that it is still soft).How badly did your filler shrink as it wouldn't have left a smooth flat surface.
BY the way Steve speaks from lots of experience and is quite articulate about what he writes and that he has the patience to explain it to you guys.
I had to as a kid with the old man (he was a painter then)1957-, had to fill miles of mahogany and walnut doors,k/cabinets and feature wall and it was all done with paste filler(silica) stain added. if it got thick you just added a little more blo(it thickened as you always used a 4 or 6" scraper to takke of the excess and put it back in the pot. wipe it out; let dry over night and brush it out with a seal coat of lacquer and then brush on 2 coats or varnish. I was 12 then that started
ron
Tung oil takes a several days to cure sufficiently to be recoated. And, it never cures hard--yes I understand it is mostly just in the pores. Tung oil also shrinks considerably as it cures. The coloring agent in the slurry filler is just boringly the same color as the base mahogany and does nothing to enhance the appearance. And yes I have tried slurry, though with oil/varnish mix, which would provide a better vehicle. .By the way, Formby's isn't tung oil of any kind, it's varnish. I'd take a wild guess that that is what you have used since pure tung oil would never begin to stiffen in a few minutes. Mostly it's very difficult to wipe oil off the surface and not pull the slurry from the pores.
The oil (or varnish) left on the surface, and there would be some (the color change of the wood, darkening it to its oiled color tells you that.) is very unevenly removed by sanding. That makes dye "take" unevenly. If you sand enough to be sure of fully removing surface oil, you can also be sure that fresh pores will be opened up.
The situations are quite different too in that the original poster said the mahogany needed to be dyed. Dye isn't suitable for exterior applications as it would fade severely in short order. But dye goes on most evenly by being flooded on bare wood. Mahogany accepts dye quite well and evenly. The only problem with mahogany is that most modern mahogany is boring: We haven't heard from the OP so my favorite schedule, which aims at the basic appearance of 18th c. antiques, may not work but here goes:
The first step is most unusual. I use a light to medium concentration yellow dye as the first step. Then I use a wash coat of shellac. Sometimes, and a bit controversially, If I aim to make the appearance a little more variable I then will either use a brown mahogany dye, which will take unevenly since the shellac has penetrated unevenly--sealing the dense parts of the mahogany and leaving the less dense portions more porous and open to the dye. (This is a more natural unevenness than would be achieved by sanding oiled wood.) A bit of experimenting is needed since the cut of shellac that works best depends on the particular wood and desired look. (If you are aiming more for the look of 19th century mahogany that is redder, you could replace the yellow dye with a medium red dye. Using yellow dye gives golden highlights, red dye mean red hightlights. By the way the best dye is powdered water soluble dye. It will make the wood look awful before it is topcoated.
More conventionally, the wash coat of shellac is followed by an application of the tinted pore filler (or areas not to be filled by an oil based stain with the same pigment,) This pigmented stain or tinted filler mostly sticks in the less sealed portions of the wood letting the dye undercolor shine through as a high light. A final seal coat of shellac isn't a bad adea. If a waterborne topcoat or a polyurethane varnish is contemplated the shellac needs to be dewaxed shellac.
Pretty much any top coat is usable over the sealed and filled wood.
Using grain filler
Al,
Follow the directions on the can of grain filler, but here are the basics:
There are two types of filler...water based and solvent based. The water based dries faster.
I always apply a coat of dewaxed shellac before I use the grain filler. It makes it easier to sand off the excess later. First, use an old brush to work the filler into the pores of the wood and then use a plastic scraper or old credit card to remove am much of the filler from the surface of the wood as possible. Scrape across the grain or at a 45 degree angle so you don't remove the filler from the pores. Do a little section at a time or the filler will dry before you can remove the excess. Then use a piece of burlap to remove as much residue as possible.
Let the filler dry for at least 2 days. Then use fine sandpaper to remove any filler that is left on the surface of the wood. You must remove every bit of it or it will be clearly visible later. The grain filler should only be in the open grain pores, not on the surface.
Then you can apply any finish you want.
Filling the grain is a chore, but the results are worth it for a project that warrants it. Hope this helps.
Jim
I wasn't going say anything since I am not an old hand
at finishing but was thinking exactly what Steve S. wrote. From my extensive study and research I must say you are getting great advice. You may wipe off down to the wood with the burlap and in theory it seams only the pores are filled but the wood cells have soaked up the oil and so would resist the dye to some degree. The silica crystals , especially when wetted with the finish will be more clear and have more depth and clarity than shredded wood fibers. The old cool guys , French polishers, used the mineral filler and so did not rely on just wood fibers to fill with.
I think the tough, flexible finish for a boat and the hard, delicate, but clearer finish on fine home furniture is apples and oranges.
Saville,
Thank you for the links to the photos of your beautiful work. Great stuff. Wow that is one tall mast !
Dye aside...
Hi all - sorry to ressurect an old thread but I'd like a little more on this.
The discussion above turned its focus towards 'paste filler' vs 'sanding slury' but focused on appearance and dye application.
What I want to know is - which of these two would give the most durable surface? I would like to produce a very smooth surface on some curved oak parts, but without having a "plasticy" coating that poly-varnish can give. I'm aiming for an oil-like finish, but with the pores filled. Appearance is not important.
Thoughts?
Many Thanks,
Chris
Dye & Fill Question
To add to Chris' question, I have a project where I was intending to dye and fill the parts before glue up but I am concerned whether the dye and/or any filler that might get on the joinery members would affect the adherence of the glue. My guess is that the dye would not affect the glue but the filler would. Pointers anyone?
Dye and wood filler
I have been wondering the same. I'm making an entertainment center with dividers and shelves out of African Mahogany and am not lookong forward to finsihing after glue up in the small spaces. I want to use dye and pore filler and would rather finish it before glung it up. I am wondering whether masking off the joints with blue tape will be sufficent to keep the dye and pore filler off the glue joints-considering how runny the dye is and how messy the pore filler process seems to be. And...maybe I don't need pore filler for the inside parts that won't show as much? Anybody have any information?
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