Home » Audio » Craftsmen » Finish for Purpleheart
Finish for Purpleheart [message #29714] Tue, 10 January 2006 00:50 Go to next message
David G. Brown is currently offline  David G. Brown
Messages: 1
Registered: May 2009
Esquire
I am making a pair of dipole speakers using two panels of Purpleheart. It is beautiful dense wood but the planks (13"x 48"x 7/8" thick) are still rough. I need to either sand them extensively myself or have them dressed at a woodworking shop. I've never worked with rough cut boards before so I'm not sure how best to proceed?

I also wondered if any one would have advise on a good finish for Purpleheart. Thanks

Re: Finish for Purpleheart [message #29715 is a reply to message #29714] Tue, 10 January 2006 07:29 Go to previous messageGo to next message
cfranz is currently offline  cfranz
Messages: 23
Registered: May 2009
Chancellor
Assuming that you want the boards flat and the edges square, your gonna need a plainer and a joiner. Find a woodshop. 48" X 13" is a LOT of hardwood to try to sand. Squaring without a joiner is darn near impossible.

If you really wanna do it yourself. Delta makes a 13" plainer for about $400 (or less). Good joiners can run as much. If your in the U.S., hit 'www.pricegrabber.com' and look for reconditioned ones. Although most of the plainers I saw were for 12 1/2".

Re: Finish for Purpleheart [message #29716 is a reply to message #29714] Tue, 10 January 2006 16:12 Go to previous messageGo to next message
GarMan is currently offline  GarMan
Messages: 960
Registered: May 2009
Illuminati (2nd Degree)
Most lumber yards will dress lumber (plane and joint) at $50-$60/hr, with mininum charge in place. Price can be higher if you didn't buy the wood from them. There may be a surcharge for your purpleheart if they consider it an "abrasive" material. Purpleheart is great at dulling blades. Should take less than 1/2 hour to dress your two planks, but consider the up-charges.

If you have the muscle, you can dress the planks by hand with a scrub plane, #4 smoothing plane, and #6 or 7 jointer plane.

Do some research before deciding on a finish. Purpleheart can take a colour from magenta-red to purple to greyish brown, depending on finish and exposure to light/air. Start with the link below.

gar.


Re: Finish for Purpleheart [message #29717 is a reply to message #29714] Wed, 11 January 2006 22:37 Go to previous messageGo to next message
Bill Martinelli is currently offline  Bill Martinelli
Messages: 677
Registered: May 2009
Illuminati (1st Degree)

If your not into spending a ton on a jointer and planer. I agree with the other guys and you should find a woodworking friend or a lumber yard, mill shop that can surface the boards for you.

Purple heart is a brilliant purple but will too soon turn bery dark and even brown in short time. any oils finish will darken the wood and with UV will turn very dark. If the bright purple is what you want to keep. Water based polyurathane will impart the least coloration. The water poly is a bad choice for figured woods since it wont bring out grain like other finishes. If you want to keep maple or oak bright, white and clear its a great choice. Extreamly durable. Look for a water poly with UV protection. The sunlight is the deal killer here.

I used to put a few coat of Armorall under the finish coat on padauk and purple heart to keep their color. Another trick is to stain or glaze the wood with its own color. you dont change anything, but it stays the same. For purple your going to need analyn dye or china pigments in a glaze. All of its lots of work and you'll need to do more reading on the topics if you choose that rout.



Re: Hey, Bill, what about pre-cat? nt [message #29718 is a reply to message #29717] Thu, 12 January 2006 04:46 Go to previous messageGo to next message
Bill Epstein is currently offline  Bill Epstein
Messages: 1088
Registered: May 2009
Location: Smoky Mts. USA
Illuminati (2nd Degree)


Re: Hey, Bill, what about pre-cat? nt [message #29720 is a reply to message #29718] Thu, 12 January 2006 12:29 Go to previous messageGo to next message
Bill Martinelli is currently offline  Bill Martinelli
Messages: 677
Registered: May 2009
Illuminati (1st Degree)
I Like pre-cat lacquer and use it almost always. I look forward to the finish after 9 months or so, because it 'warms up"
I did some work and finished it with water borne poly 4 years ago and the work is just as stark and bright today. All the products that say non-yellowing, just yellow a little less. The water poly in the less expensive brands is going to impart the least amount of amber and warming tones over time. The more expensive commercial products are trying to be more like lacquers and varnish with grain poping tone. Try Minwax® Polycrylic®

Purpleheart Dye and Padauk question [message #29721 is a reply to message #29717] Sun, 15 January 2006 19:03 Go to previous messageGo to next message
Shane is currently offline  Shane
Messages: 1117
Registered: May 2009
Illuminati (3rd Degree)
Woodcraft makes a purple dye just for doing purpleheart. I have used it with good results. It was exactly the same color as the fresh cut wood. Just let it dry overnight and topcoat to suit.

Bill, what did you finish coat with after armoralling the padauk? I have a couple of 8 x 6's of padauk and purpleheart I've been saving to do amp chassis' with. I made a heaphone rack out of purpleheart and padauk where I dyed the purpleheart, but left the padauk alone and finshed with about 8 coats of Formby's Tung Oil.

Re: Purpleheart Dye and Padauk question [message #29722 is a reply to message #29721] Sun, 15 January 2006 21:47 Go to previous messageGo to next message
Bill Martinelli is currently offline  Bill Martinelli
Messages: 677
Registered: May 2009
Illuminati (1st Degree)

I'm on how the padauk color is after time? I always find oil finished to be very darkening after exposure to sunlight. Linseed oil is particularly the worst. but if you want something dark...

I was looking for a way to keep that bright orange red in padauk long after the top coat. A friend told that this armor-all was a polymer and would help block out UV and keep the color of the wood.
I tried it and I was only able to see this project for about a year after and it looked fine to that point. In the 80's when this was done I was shooting Sherwin Wiliams, Water White lacquer.


Re: Purpleheart Dye and Padauk question [message #29723 is a reply to message #29722] Mon, 16 January 2006 10:57 Go to previous message
Shane is currently offline  Shane
Messages: 1117
Registered: May 2009
Illuminati (3rd Degree)
The tung oil darkened it a little, but only to a deep orange color--still very pretty. I made that stand about 4 months ago and there is definitely no change in the color so far. They say osage does the same thing, but I've got bows I've made out of the stuff 6-7 years old that have seen a lot of sunlight in use and they are still very yellow with very little darkening. So the time to actually change may be exceedingly long.

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