Mahogany Finish

[Matt Campbell]

So I'm building a Shaker style shelf. I put some polyurethane on a small piece last night, and I'm not satisfied with it. What suggestions do you all have for finishing? Has anyone ever used potassium dichromate? I have considered that followed by a few coats of tung oil. I will also try just tung oil tonight. Thanks for any help.

[David DeCristoforo]

P.D. will give your mahogany a beautiful color. About 2 - 3 tablespoons per quart of water (warm to dissolve but not too hot). Whatever you use after that is your call but I would agree with you about the poly (never did like to look of that stuff). An oil finish would further enhance the color and figure. Please keep in mind that P.D. is considered very toxic and is a known carcinogen so proper protection (rubber gloves, apron, respirator and eye protection) is a must.

[Matt Campbell]

I googled but could not find a source for potassium dichromate. Can you tell me where to find some? Also, thanks for your help. I believe this is the way I will go with it.

[Matt Campbell]

Oh, and I assume application can be done by hand-rubbing or using a foam brush?

[Tim Malyszko]

I googled but could not find a source for potassium dichromate. Can you tell me where to find some? Also, thanks for your help. I believe this is the way I will go with it.


http://www.artchemicals.com/Potassium-Dichromate-Granular-TechnicalBRCAS-7778-50-9-P380C0.aspx

[Matt Campbell]

Thank you. I actually just found that website. Here also is some information from David Marks who apparently uses this frequently.

http://www.djmarks.com/stories/faq/where_can_i_get_potassium_dichromate_46686.asp

[Steve Schoene]

Another source is Olde Mill Cabinet Shoppe, www.oldemill.com which has it and lots of other chemical dyes for wood. Remember this is a poisonous substance and accordingly care must be taken.

You can achieve much of the same effects using water mixed analine dyes. These are safer, and also a bit less risky, since if your wood is not entirely from the same tree the chemical dye can react differently on different boards. In fact, there are some subtle effects that enhance the figure in the wood that can be achieve with dyes that don't result from the use of potassium dichromate.

[Tim Malyszko]

Thank you. I actually just found that website. Here also is some information from David Marks who apparently uses this frequently.

http://www.djmarks.com/stories/faq/w...mate_46686.asp

I took a finishing class with David Marks a few months ago and he demonstrated the Potassium Dichromate finish on mahogany and it turned out great.

[Larry Fox]

If it is just a display shelf and won't see much abuse BLO followed by shellac is a good thing to try. If you want it to look really rich maybe try a French Polish. I have never tried (nor heard of) the chemical you mention - sounds dangerous though.

[Lance Sleeper]

I googled but could not find a source for potassium dichromate. Can you tell me where to find some? Also, thanks for your help. I believe this is the way I will go with it.
If you don't want to mess with the PD, then Household Lye will do the same thing. Red Devil is the name brand, although there are drain cleaners that do the same thing. Caustic, but not quite as nasty and easier to find. Same basic mix. I have used it very successfully.

[Dave Sidlow]

I am interested in using potassium dichromate on a mahogany bed I am making. I've searched the Internet and found some common suggestions: very toxic, use protection, thin coat and wipe off and dry. However, I have a few more questions: What about the toxicity of the dust created while sanding PD treated wood? Do you need to wash the wood with water after treatment?

[Greg Cole]

Another vote here for analine dyes for mahogany per Steve's comment above.
I built a hall table out of mahogany and used a finishing schedule that Steve modified for me. It's absolutely gorgeous albeit a wee bit of work.
#1) Lemon yellow dye
#2) Light wash coat of DW shellac @ 1 lb cut
#3) Brown mahogany dye
#4) Standard cut schellac @ 2 lb cut & a couple coats
#5) Oil based pore filler- can easily be skipped again up to you.
#6) See step 4 if you proceed with step 5.
#7) Burnt Umber Glaze
#8) Just one more coat of shellac, ok maybe 2.
#9) Arm- R -Seal top coat application. 2-3-4 coats, up to you
#10) Rub out and wax.
I forgot the grain raising step before applying dyes, but if you use alcohol based dye nevermind anyway. I use water base dye & apply by hand so grain raising is an important step not mentioned above. Sanding between steps is up to you or your ability to apply shellac.
Honestly, it sounds-reads like alot more work and time than it really is.
And as Steve advertized, after the lemon yellow dye the project will look terrible. But hang in there, it's worth it. The yellow dyw gives the lighter tones in natural mahogany a nice highlight under the other dye and schellac coats.

FWIW.
Greg

[harry boyer]

I have a bunch of mahogany to finish. Would you fill the grain before using P. D. or after. I was thinking I could seal it with shellac after the P.D. and then fill as usual.

Thanks

[harry boyer]

Thanks all for the inspiration. I'd heard of this treatment and had seen David Marks vid. I got out the yellow pages and found a chemical supply. I think he was a bit high but I bought 3 table spoons for $5 and one of those non-corrosive quart plastic containers for another $2 . I'm experimenting with scrap but really like the results. I haven't tried the tongue oil. Might not use it because of the drying time. I think two or three coats of shellac, sand between coats and a few coats of wipe on poly satin , and a final polish with a good quality brown furniture polish.

The project is a dressing room 13' wide, The ends will come back abt 4' with 45degree at corners. floor to ceiling closet organizer. all of the front surface will be drawer fronts or Shaker panel doors. Anyhow thanks for the advice. I was looking for something simple and fairly easy to do on the finish.The potassium chromate does even out the African Mahogany. Still looks natural to me. I tried General Finishes Brown Mahogany get stain after the seal coat, and a wood filler and wasn't that happy with it. Too dark I guess.

Just an observation. Years and years ago in art school (66 graduate) I learned that even the best artists have a hard time knowing when to stop working on a piece. Everyone I knew including myself had this tendancy. Harder and more complex isn' necessarily a sign of good work. I don't know what the "best" is either. I do know that we can overwork something to the point of taking the life out of it. KISS!
Thanks again! I'm off to work on the mockup of the archer panel doors.