I am entirely new to this ng, though I subscribe regularly to a couple of others.
A Google search showed that this topic has been addressed before to some extent, but I couldn't find complete coverage of my question. If I'm breaking your local netiquette rules, I apologise in advance.
The question is this:
Can Danish Oil (Cabot brand) be used as a grain filler/primer for polyurethane (same brand) and/or nitrocellulose (different brand)?
The project is an all-mahogany guitar on which I want a thin high quality gloss finish that brings out the natural look of the timber. There is no plastic in the construction, but there is some MOP. I would be using spray can or brush on. I would, in fact, be satisfied to leave it with a Danish Oil finish, but a gloss topcoat would be a big bonus.
I have used Watco oil, which is one form of Danish oil, the technique I use is to apply a liberal amount of Watco and rub it into the workpiece with 400 wet & dry, using a figure 8 motion, this forms a slurry which acts to fill in the grain. Rub the excess off after about 10 mins and repeat another one or two coats of Watco, you should get a reasonable shine at this point. You can apply more Watco if you wish, but you can also apply a rub on poly if you desire, you need to wait a minimum of 72 hrs. after the last coat of Watco.
The process I had planned involved a lot of soaking and wet sanding over many applications, as I have finished gunstocks in the "London" style with linseed and (cheating here) accelerator. The Danish Oil should be easier, because it dries hard in a fairly short time, ie about a week. The link gave me a good idea of time scales, which I was guessing would be shorter (minutes rather than hours) than those he suggests.
FWIW, I checked the MSDS sheet on the Cabot's Danish Oil, and the main ingredients are polymers and solvents, no oil listed, unless it is a component of the small amount of unspecified ingredients.
We were given a antique Singer sewing machine that had been stored in a dry cellar for many years.The top laminated wood was starting to peel a bit and i gave it two coats of boiled linseed oil to prevent any more 'lifting'.Was i wrong to do this? The rest of the machine is in very good condition.
If you mean can you over coat a Danish oil with poly and have it stick, yes you can but let it cure first.
If you are asking if you can seal the open pores of mahogany with it the practical answer is no.
Danish oil is, well, an oil finish. It is not meant to build and form a surface finish. Oh, put enough of the stuff on and it eventually will build to a soft, possibly gooey surface but if you want a surface finish you'd be better served by using a surface finish rather then trying to make a finish do something it isn't actually meant to do..
If filling the open pores of the mahogany is your aim you can use a commercial wood filler, coats of shellac or thinned coats of your ultimate finish, applied and sanded back till the pores are filled to the level of the surrounding wood.
In other words you want something that will build, be compatible with your finish, not detract from the looks of your finished product and can be easily cut back until the pores are filled.
Eric gave you the link to the article, but not to the rest of my www site (not a problem, Eric). There is another article on the site which is more geared towards the actual filling process.
Many modern Danish and 'Tung' oil finishes are more similar to thinned varnishes than they are to true traditional oil finishes.
You can indeed fill with oil, but it can be a very long and slow process. And you can topcoat over an oil finish with a film finish, although I still don't understand the proclivity of many people to do so on a regular basis. If you choose to do this, you must be certain to allow the oil finish to fully cure prior to topcoating.
Fillers are made for filling, and a pore filler is generally the right product to use. It's a single-step process when done correctly. French polishing is another possible method of filling, and since the process uses shellac, it dries quickly and generally causes no problems with subsequent topcoats.
This falls into the been there, done that category, and you may find the following link interesting:
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all the way down. When you get tired of that, you can use the link at the bottom of the page to go find the filling article.
The method I used (and have used countless times over the years) was to seal the wood with sanding sealer, then fill the pores of the rosewood and mahogany with tinted pore filler. The sanding sealer prevents the tinted filler from staining the wood. When the filler is dry, you sand off the sealer and proceed with sealing and topcoating. A very straightforward method that leaves the actual wood crystal clear and clean, while filling the pores with a suitably-colored filler material.
John
John Paquay snipped-for-privacy@insightbb.com
"Building Your Own Kitchen Cabinets"
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Glory and Passion No Longer in Fashion The Hero Breaks His Blade. -- Kansas, The Pinnacle, 1975
Thanks for the replies. I have decided to go with Danish Oil on this guitar, since I want a very thin finish, and the satin look is OK for this style of instrument, a kona.
FWIW, some Cabot Danish Oil I put on a bit of metal a couple weeks ago has set as hard as rocks, so I'm optimistic it will not end up gooey. I think the "oil" description may be misleading. From its MSDS and behaviour it seems more like a very slow drying polyurethane that doesn't have much of a "tacky" phase.
I'm very much feeling my way with this, as I seem to have no natural ability with finishing - most of my experiences have been bad ones. I could get the job done professionally with nitrocellulose, but that would cost maybe US$700, and anyway I would at least like to try it myself. A major technical difficulty is that the bridge and neck are already attached, so I have to try and get a neat look in the angles created thereby.
The danish oil is very easy to use, and at least I understand the wet sanding process, more than I can say for dedicated grain fillers and sealers.
The brand of Danish Oil I can get (Cabot's) seems to set hard (couldn't mark it with my fingernail when set on a hard surface) in a few days, and the final finish will be very thin, also highly desirable. (I read somewhere that medieval lutes were finished with egg white!) I anticipate that the thinness will make it fragile, but no worse than french polish, and hopefully, just as easily repaired.
Another plus I have found is that Danish Oil seems to be highly compatible with super glue, so that any repairs I missed in the initial stages, such as slightly open seams, can be fixed on the run without a lot of work.
I thought I might try a final wash coat to get a gloss finish. Can you suggest a slow evaporating solvent to use as a thinner, which will allow time to apply the wash with a pad?
Mineral spirits is relatively slow to evaporate, much more so than naphtha (paint thinner). You may still have to work fast, though. I'm not familiar with the Cabot's Danish oil or how quickly it tacks up.
You might opt for a wiping varnish, which would be compatible with the Danish oil. You could thin the varnish further if needed, but it will give you a nice, very thin topcoat, and you should have at least 15 minutes or so to get it applied before you begin to have problems with drying. I personally like General Finishes 'Royal Finish', but there are others that are similar. Just be sure your application pad is absolutely lint-free. Definitely worth a test trial.
John
John Paquay snipped-for-privacy@insightbb.com
"Building Your Own Kitchen Cabinets"
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Glory and Passion No Longer in Fashion The Hero Breaks His Blade. -- Kansas, The Pinnacle, 1975
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