I have mixed my own blend. Fine Woodworking magazine often features articles on finishes. One finish was a blend of oil, spar varnish and thinner. I don't remember the exact ratio, but I'll bet someone has the issue and an index. I like linseed oil used in this mixture and find the combination gives a great finish with fewer coats than using oil alone.

There ain't no such thing as a "best" finish for all situations; it all depends on what you want to achieve. That said, there's no reason that blends of compatible finishes can't work.

Well, about 10 years ago I bought a quart ($40!) of Sutherland Welles polymerized tung oil from Garrett Wade in New York. I refinished an antique drop leaf table with it. It took probably 6 coats, but it came out spectacularly. Best finish I've ever used. Looked absolutely perfect, no wipe marks. Just perfect.

I now need to finish another table and am considering buying another quart. But I also have a quart of 100% pure tung oil laying around and was thinking of tweaking it for use on the table.

I think Sam Maloof also adds beeswax. I like to use just a bit of tung oil (maybe 10%) with the poly and thinner, then wipe it on. I do that for a couple coats, then a few coats without the added tung oil.

The blend you mentioned is a common one. You can also use boiled linseed oil as a substitute for the tung oil or varnish in place of the poly or naptha in place of the mineral spirits. All depends on what you have at your disposal and what you want the finish to achieve.

This finish is fine for many applications, but certainly not the best in all applications. It is easy to use, produces nice results and is readily available and cheaper (especially when you use BLO in place of tung oil), than equal volumes of commericially available Danish oils (which is want such a blend is generally called).

Finishes should be matched to the individual project based on how the piece will be used, what environmental conditions it will be subjected to and how you want it to look & feel.

Just for my edification, I ordered a quart of J.E. Moser Polymerized tung oil from Woodworkers Supply, which seems to be similar to the Sutherland Welles product, but at about 1/3 the cost. I'm going to use it to see if works as well as the SW. I'll update this post in a few weeks when it's done with my results.

The mixture I use of my wood products are as follows:
1/3 PURE tung oil ( Think you can get from Rocklers)
1/3 BLO (boiled linseed oil)
1/3 polyurethane
This may be the custom tung oil mixture you are thinking about.
You can mix this in a glass container with lines marked in even 1/3 lengths on the glass, any amount you wish to make. Just pour to the line with each ingredient, then stir. I use this as a wiping finish, with a soft cloth like a piece of tee shirt.
If the wood is to be used inside I use either satin or gloss, depending on the finish I desire.
If the wood is to be used outside, I use SPAR polyurethane to protect from UV light. Usually three coats on the outside wood with a light sanding between coats with 400 grit sandpaper.

Has anyone used Sutherland Welles tung oil finishes and stain on eastern white pine floors? The staining is the tricky part - they say to seal the wood first and then apply stain. Any comments?

see the article below

Here is a link that might be useful: Oil finishes

Jim,
How would increasing the percentage of either of the three ingredients change the finish, say if you wanted more protection from moisture and mildew, or a smoother finish?
If you were going to finish, say an mohagany exterior door, would you still keep it at 1/3 all around?

I would add more urathane for finishing the exterior door

Here is a link that might be useful: Mission Grounds Gourmet Coffee

I used a similiar mix on a exterior T-111 rough sawed plywood I used on a guesthouse here in SoCal. Lot's of sun/UV abuse on this. I was told by a local paint store guy who had an old school formula which isn't "legal" now here in Ca. He advised me using a Duckback/Superdeck oil based sealer/stain mixed with the linseed, tung and slightly thinned with thinner to help roll on and penetrate the wood...also helps spread the tung, linseed evenly. I'm looking around for the formula now. I need to re-apply at least on of the sides that gets most of the sun on this T-111...I'll start with a light steel brushing to help remove any dried stain that needs to come off as well as ..I'm told to use a wood cleaner before applying the new mix. I'm not sure if I need to use the same formula or not...If anyone knows the formula and are what I should use for the upkeep second coating (3 1/2 years later) I'd appreciate it. Thanks, Terry in SoCal