Total Finishing Supplies

Professional Finishing

You are not logged in. [ Login ] Why log in
(NOTE: Login is not required to post)

undercatalyzed conversion varnish

6/2/19       
nick Member

Greetings all-

About 2 years ago I built a large conference table (1 1/2" baltic birch exposed edge plywood, cypress veneer with solid wood inlay details). Apparently it didn't get used much until recently, but now there are major finish issues. My used-to-be-trustworthy finisher apparently undercatalyzed the conversion varnish finish, as it seems to have never fully cured/hardened. If you write on a piece of paper on the table, then lift the paper, you can see the faint outline of the writing in/on the finish. It gets dirty easily and seems to have a slightly gummy feel to it (looked great when it was originally delivered).
One finisher suggested a light sanding followed by water-based poly on top (this doesn't sound right to me but he says he's seen it work). Another finisher told me a slightly overcatalyzed CV on top after light sanding could work but is risky. I've read a normally catalyzed CV on top might fix it as well.
Obviously I'd prefer the easiest/fastest/cheapest fix, but it needs to be done right so I know that might mean stripping it completely (buries face in hands). If this is the ultimate decision- what is the best way to strip CV? The table is comprised of 4 sections which, together, are 5'x16', legs are removable steel. Thanks for any and all advice.
Also if anyone knows/recommends any good finishers in south Florida who might be willing to take on this nightmare, please let me know, thanks! Nick

6/3/19       #2: undercatalyzed conversion varnish ...
DannyB Member

Stripping is your only real option.

The catalyst needs to be able to force crosslinking *everywhere*, not just a thin layer on the top/etc.

It's basically impossible to turn it back into a completely liquid form and have the catalyst mixed and agitated into the result in the right ratio.

Even if you could somehow guess the ratio right enough to not cause white spots due to overcatalyzation, the thinner is highly unlikely to melt it all the way through and thoroughly mix it.

If you had screwed up one thin, small, coat, you might be able to get away with something here because you may be able to melt the entire film.

But a conference table would normally have whatever the max allowed is :)

So unless you have a magic way of guaranteeing your thinner is going to melt *all* of it, *all* the way down, and then a way of ensuring the catalyst makes it thoroughly into the result, all the way to the bottom as well, you are screwed here.

Wish i had better news.

Usual approach is to go get xylene and strip it all.

6/3/19       #3: undercatalyzed conversion varnish ...
rescraft

I'm assuming your "used to be finisher" will not take any responsibility for his mistake? Did you have a contract w/him?
Can he at least help pay for the materials needed for the fix?

6/3/19       #4: undercatalyzed conversion varnish ...
Nick Member

Thanks-
It’s complicated- the finisher who did it is out of business and on death’s door with a myriad of really bad health issues- maybe he never used adequate safety measures because he is really falling apart. I suspect he messed it up in the first place because he was all screwy on medications at the time. Suffice it to say he’s out of the picture unfortunately. Straight xlene with scrapers and rags? Have you ever used that MAGIC 555 stuff?

Plan B might be to slap the whole thing with laminate (buries face in hands). I’m hopeful the customer will have mercy on me and share the cost. Anything peculiar about contact cement sticking to conversion varnish?
THANKS!

6/3/19       #5: undercatalyzed conversion varnish ...
DannyB Member

Staring at a bunch of SDS for Magic 555, i don't think most will work.

Depending on how fast you want to do it, xylene or acetone will be your fastest way.

If it was not catalyzed properly, acetone should go right through it and be cheap in bulk.

It's also VOC exempt.
But you'd need to be careful as acetone will go through almost anything you've got protective clothing wise.

If you want something "less dangerous", something NMP based will probably work, and do a more thorough job, but it will take a while to work.

Citristrip is NMP based (right now) as an example.

There are other variants you could use.

I honestly would try to just pay someone to dunk tank strip it or something (depending how big a conference table we are talking)

6/4/19       #6: undercatalyzed conversion varnish ...
Shane

I'd build from scratch before I went down that path... IMO

6/4/19       #7: undercatalyzed conversion varnish ...
dan shaf Member

For stripper, get a couple of gallons of Dad's. It's got a decent amount of methylene chloride in it, so it's potent. It has no ammonia in it and no lye, so it won't darken any of the woods.

Score the existing finish with 100 grit, just to create a scratch pattern in the finish. This allows the MC to work its way into the finish film to break it apart and to cause it to want to unbond (mechanically) from the substrate.

Use a boatload of woodshavings to clean off the sludge instead of rags, instead of steelwool, instead of Scotchbrites.

Wear thick neoprene gloves. If stripper gets on your skin, it will sting. Remove the stripper from your skin with a rag soaked in water. A solvent-soaked rag drives the stripper into the skin.

Before stripping, yes, do try the over-catalyzed conversion varnish. Lightly scuff your existing finish, first.

The extra-hot CV will often -- not always -- kick the undercatalyzed finish underneath. Been there, done that, with proper success.

6/5/19       #8: undercatalyzed conversion varnish ...
Leo G Member

The over catalyzed conversion varnish will either wrinkle the existing coating or it will fail prematurely because it's over catalyzed.

Either put a correctly catalyzed conversion coating on it (after light scuff) or put a vinyl sealer coat on it, catalyzed (ask your rep for percentage. I know 1% is good for MLC vinyl sealer). And then apply the properly catalyzed conversion varnish coating on top of that after a light scuff.

6/5/19       #9: undercatalyzed conversion varnish ...
Shane

I realize a lot of us have dealt with this issue at one time or another. Sure some of us may have shot another coat on it and called it good... the customer was probably pleased.... but the chemistry isn't going to lie... Sure the coating you put on top happens to lay out and cure on the surface...…. what's underneath is still a problem.... we all know a hard finish on top of a layer of soft finish is going to be the weakest link... it will fracture.... just when will it start? If you can sleep at night knowing it's wrong that's your deal..... Strip it and start over or remanufacture the product...

6/5/19       #10: undercatalyzed conversion varnish ...
rich c.

Two thoughts, cypress is really soft and are you sure the writing isn't showing in the wood. Second, was some odd kind of cleaning chemical used by a new cleaning crew lately? Hard to imagine that in 2 years no one complained about sticky feel. It should have felt sticky when it left the shop if it was under catalyzed. Don't waste the time and money to apply something on top. Strip it down, do it right.

6/8/19       #11: undercatalyzed conversion varnish ...
nick Member

Thanks all- I really appreciate the responses! I too thought about the softness of cypress, but the same effect occurs in the hard edge grain of the baltic birch ply. The possibility of a cleaning crew's wax cleaning product would be a welcome discovery (to put it mildly); I plan to do another site visit to investigate more thoroughly. It's hard to describe the feel- it's not sticky, but kind of waxy. Fingers crossed someone just put a dumb cleaning product on it that can be easily removed.
The finish seemed fine when I first delivered it; good sheen, not sticky. I had to stack the leaves to transport (blankets between of course) and had them upside down on the floor on blankets to screw on the legs. When I originally left it was gorgeous.
It's also likely the space has been un-conditioned on and off and possibly getting very hot in the Miami heat- I don't think that would affect a proper CV finish, but maybe?

6/9/19       #12: undercatalyzed conversion varnish ...
JeffA

After reading your last post, another cause of the issue could be the varnish was over catalyzed. What you are feeling is the excess catalyst leaching out and laying on the surface. This doesn't always show up right away like you mentioned during the initial delivery and it also depends on how much it was over catalyzed. If this is the issue, it's an easy fix. Take 1 gallon of water and mix in a box of baking powder. Wipe the area with a damp cotton rag of the water/baking powder mixture. And dry off the area with another rag. You may need to do this a few times to get it all off. Don't reuse the damp rag, only use it once. And don't redip the dirty rag, always get a clean one.


Post a Response
  • Notify me of responses to this thread
  • Subscribe to email updates on this Forum
  • To receive email notification of additions to this forum thread,
    enter your name and email address, and then click the
    "Keep Me Posted" button below.

    Please Note: If you have posted a message or response,
    do not submit this request ... you are already signed up
    to receive notification!

    Your Name:
    E-Mail Address:
    Enter the correct numbers into the field below:
     

    Date of your Birth:



    Return to top of page

    Buy & Sell Exchanges | Forums | Galleries | Site Map

    FORUM GUIDELINES: Please review the guidelines below before posting at WOODWEB's Interactive Message Boards (return to top)

  • WOODWEB is a professional industrial woodworking site. Hobbyist and homeowner woodworking questions are inappropriate.
  • Messages should be kept reasonably short and on topic, relating to the focus of the forum. Responses should relate to the original question.
  • A valid email return address must be included with each message.
  • Advertising is inappropriate. The only exceptions are the Classified Ads Exchange, Machinery Exchange, Lumber Exchange, and Job Opportunities and Services Exchange. When posting listings in these areas, review the posting instructions carefully.
  • Subject lines may be edited for length and clarity.
  • "Cross posting" is not permitted. Choose the best forum for your question, and post your question at one forum only.
  • Messages requesting private responses will be removed - Forums are designed to provide information and assistance for all of our visitors. Private response requests are appropriate at WOODWEB's Exchanges and Job Opportunities and Services.
  • Messages that accuse businesses or individuals of alleged negative actions or behavior are inappropriate since WOODWEB is unable to verify or substantiate the claims.
  • Posts with the intent of soliciting answers to surveys are not appropriate. Contact WOODWEB for more information on initiating a survey.
  • Excessive forum participation by an individual upsets the balance of a healthy forum atmosphere. Individuals who excessively post responses containing marginal content will be considered repeat forum abusers.
  • Responses that initiate or support inappropriate and off-topic discussion of general politics detract from the professional woodworking focus of WOODWEB, and will be removed.
  • Participants are encouraged to use their real name when posting. Intentionally using another persons name is prohibited, and posts of this nature will be removed at WOODWEB's discretion.
  • Comments, questions, or criticisms regarding Forum policies should be directed to WOODWEB's Systems Administrator
    (return to top).

    Carefully review your message before clicking on the "Send Message" button - you will not be able to revise the message once it has been sent.

    You will be notified of responses to the message(s) you posted via email. Be sure to enter your email address correctly.

    WOODWEB's forums are a highly regarded resource for professional woodworkers. Messages and responses that are crafted in a professional and civil manner strengthen this resource. Messages that do not reflect a professional tone reduce the value of our forums.

    Messages are inappropriate when their content: is deemed libelous in nature or is based on rumor, fails to meet basic standards of decorum, contains blatant advertising or inappropriate emphasis on self promotion (return to top).

    Libel:   Posts which defame an individual or organization, or employ a tone which can be viewed as malicious in nature. Words, pictures, or cartoons which expose a person or organization to public hatred, shame, disgrace, or ridicule, or induce an ill opinion of a person or organization, are libelous.

    Improper Decorum:   Posts which are profane, inciting, disrespectful or uncivil in tone, or maliciously worded. This also includes the venting of unsubstantiated opinions. Such messages do little to illuminate a given topic, and often have the opposite effect. Constructive criticism is acceptable (return to top).

    Advertising:   The purpose of WOODWEB Forums is to provide answers, not an advertising venue. Companies participating in a Forum discussion should provide specific answers to posted questions. WOODWEB suggests that businesses include an appropriately crafted signature in order to identify their company. A well meaning post that seems to be on-topic but contains a product reference may do your business more harm than good in the Forum environment. Forum users may perceive your references to specific products as unsolicited advertising (spam) and consciously avoid your web site or services. A well-crafted signature is an appropriate way to advertise your services that will not offend potential customers. Signatures should be limited to 4-6 lines, and may contain information that identifies the type of business you're in, your URL and email address (return to top).

    Repeated Forum Abuse: Forum participants who repeatedly fail to follow WOODWEB's Forum Guidelines may encounter difficulty when attempting to post messages.

    There are often situations when the original message asks for opinions: "What is the best widget for my type of shop?". To a certain extent, the person posting the message is responsible for including specific questions within the message. An open ended question (like the one above) invites responses that may read as sales pitches. WOODWEB suggests that companies responding to such a question provide detailed and substantive replies rather than responses that read as a one-sided product promotion. It has been WOODWEB's experience that substantive responses are held in higher regard by our readers (return to top).

    The staff of WOODWEB assume no responsibility for the accuracy, content, or outcome of any posting transmitted at WOODWEB's Message Boards. Participants should undertake the use of machinery, materials and methods discussed at WOODWEB's Message Boards after considerate evaluation, and at their own risk. WOODWEB reserves the right to delete any messages it deems inappropriate. (return to top)


  • Forum Posting Help
    Your Name The name you enter in this field will be the name that appears with your post or response (return to form).
    Your Website Personal or business website links must point to the author's website. Inappropriate links will be removed without notice, and at WOODWEB's sole discretion. WOODWEB reserves the right to delete any messages with links it deems inappropriate. (return to form)
    E-Mail Address Your e-mail address will not be publicly viewable. Forum participants will be able to contact you using a contact link (included with your post) that is substituted for your actual address. You must include a valid email address in this field. (return to form)
    Subject Subject may be edited for length and clarity. Subject lines should provide an indication of the content of your post. (return to form)
    Thread Related Link and Image Guidelines Thread Related Links posted at WOODWEB's Forums and Exchanges should point to locations that provide supporting information for the topic being discussed in the current message thread. The purpose of WOODWEB Forums is to provide answers, not to serve as an advertising venue. A Thread Related Link that directs visitors to an area with inappropriate content will be removed. WOODWEB reserves the right to delete any messages with links or images it deems inappropriate. (return to form)
    Thread Related File Uploads Thread Related Files posted at WOODWEB's Forums and Exchanges should provide supporting information for the topic being discussed in the current message thread. Video Files: acceptable video formats are: .MOV .AVI .WMV .MPEG .MPG .MP4 (Image Upload Tips)   If you encounter any difficulty when uploading video files, E-mail WOODWEB for assistance. The purpose of WOODWEB Forums is to provide answers, not to serve as an advertising venue. A Thread Related File that contains inappropriate content will be removed, and uploaded files that are not directly related to the message thread will be removed. WOODWEB reserves the right to delete any messages with links, files, or images it deems inappropriate. (return to form)
    Sponsors
    • SAMES North America Corporation
      Precision Spraying Solutions From Pumps To Complete Application Systems-Design and Manufacture of Process Equipment Including Airspray, Airmix, Airless, Rexson Dispense, Electrostatic and Powder Coat
    • Unique Machine & Tool
      Industrial Machinery for Door and Drawer Production
    • TotalFinishingSUPPLIES.com
      Solutions and supplies from spray tips to spray booths for all your woodworking needs
    • Carter Products
      Band Saw Guides, Blades, Wheels, Tires, Line Lasers and 2D Projectors, Wide Belt Sanding Accessories, Vacuum Holding Systems and More
    • EX-FACTORY INC.
      Offering New & Used Woodworking Machinery including Auctions & Liquidations
    • Supergrit Abrasives
      Industrial Quality Abrasives Manufactured by Leading US and Foreign Companies
    • Simantech
      New & Used Machinery, Supplies, Tooling, Parts, and Abrasive Products

    Become a Sponsor today!