Oxalic acid use without total refinishing


Jayblay

Recommended Posts

Hi all, 

I have an antique tansu that I am trying to restore. The top has a couple of dark water rings. I would like to restore the original patina while removing these stains. Could I apply oxalic acid to the stained wood only or would this lighten those areas and make the blemishes look worse? Any other thoughts? 

 

Thanks!

image.jpeg

Link to comment
Share on other sites

Two thoughts....

I know you have asked this before with no response. It may be that no one here has the experience to help. I would suggest trying this out on a drawer bottom, case back, or other area that will be hidden from view. If it does not damage the current patina, the worst case would be a failure to remove the staining. 

If you don't intend to refinish, why not just leave the water rings? The piece already has a well used appearance. 

Link to comment
Share on other sites

FYI, tried a sample of oxalic acid (slurry of bar keepers friend) and it looked fine on the back of the piece. It was lighter but a top coat of briwax made it look uniform. 

 

Then I proceeded to lighten the stains on the top of the piece. The staining did improve but the areas are now bleached and they stand out even more than the stains despite 2 coats of briwax. I should have left well enough alone!

 

i can take off the wax and touch up the area with colored pencils and spray shellac or I could just leave it alone. Any thoughts. Lesson learned?.

image.jpeg

Link to comment
Share on other sites

1 hour ago, drzaius said:

It's pretty much destroyed now. With careful use of dyes & finishes it could be refinished so it has the look of an older piece. Is this a valuable antique who's value would be destroyed by refinishing?

No not a valuable piece per say. Just a nice piece that we want to enjoy in our home for personal use. 

 

I think your right that refinishing the top only is not a bad ideal. The sides and drawer fronts look great with briwax so don not need to be refinished. I will have to carefully remove the wrought iron off the top prior to refinishing which may be a pain. 

 

The color of the top may be lighter after refinishing. If I need to darken it up I could always use some dark tung oil prior to briwax. I will do a test patch on back. 

1 hour ago, Mike. said:

Are you sure it is an original piece with the original finish?  It looks like stained pine or fir to me.  I know tansu are typically made from cypress or cedar, and it could be one of those.  It is  hard to tell with the heavy pigment stain. 

Personally I don't understand the difference between patina and watermarks.   I guess patina is the damage you want.  Kind of like a weed is just a plant you don't want in your garden, whereas as a wildflower is something you do want. It seems awfully subjective, even though I know patina is trendy nowadays.  

You really can't have your cake and eat it too.  Anything you try to do to fix the watermark will also remove your "patina".  The watermark is damaged finish.  The "patina" sits on top of the finish.  

Definitely an original piece from Japan. The pictures don't do it justice. 

Link to comment
Share on other sites

If you decide to refinish the top, then completely remove the finish from most of the top, leaving a sample area intact. Then experiment with stain/dye/finish until you find the right combination.

If you rely on adding some tung oil to darken it up, you may get the wrong color from that. Start by putting a little of whatever top coat you're going to use & see what that gets you. Then whatever hue is lacking, add a little of that to the next test spot, then add the top coat & see how it looks.

Throughout this process, make careful notes about what exactly you're laying down so you can reproduce that. It's easy to just try a drop of this & a dab of that without writing it down & then you can't reproduce that when you do the actual piece. I know this from sad experience.

I like working with dyes. You can get a selection of just the basic primary colors: red, yellow, blue & then blend them to get any color you need. Dilute them lots so you can control the saturation with layers.

It will take quite a bit of this trial & error before you get it right, but when you do it'll feel like a million bucks. Then strip off the whole top & apply your recipe. Good luck with it.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.