Ludwig cortex finish removal - what a pain!

Discussion in 'The Builders Workshop' started by JazzDrumGuy, Mar 13, 2019.

  1. JazzDrumGuy

    JazzDrumGuy DFO Master

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    I have a 9x13 B/O badge concert tom that I got in a large shell acquisition. It's basically useless to me. However, I wanted to strip it to practice some painting/finishing techniques (duco and bursts) for a few upcoming projects.

    I thought it was wrap, but it was much harder than that. I think it was cortex - stiff, hard and inflexible - and it took nearly 2 hours to remove using a heat gun and a 1" chisel......what a pain!

    The good news is that there was no shell damage and the virgin maple is white and nice!

    However, anyone have a better solution to remove this stuff in the future?
     
  2. Hop

    Hop DFO Veteran

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    From what I've read in other threads, you worked the best solution. I think others have found the cortex to shatter/shard during the removal process and the only way to tame it was to warm the material with a heat gun as you mentioned and to work slowly.

    I've not read of there being any practical solvent to loosen/dissolve the glue as the cortex is not a permeable material and prying the material up and squirting a solvent underneath seems like it is far more problematic than the heat/pry/break method.
     
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  3. Pimp-a-diddle

    Pimp-a-diddle Very well Known Member

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    A finish like that makes me wonder how hard it would be to remove the outer finish from a Ludwig Neusonic or a Sonor SQ1? I'm not sure if those are separate plys or what.
     
  4. Olderschool

    Olderschool DFO Veteran

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    I stripped an entire Cortex kit with your "method"......a heat gun and a putty knife. Can't really think of a better way....
     
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  5. JazzDrumGuy

    JazzDrumGuy DFO Master

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    I am glad I only have the one tom.....and that stuff is harsh. I sliced my finger on it....ouch!
    And yes, chips, shards and flying debris - not very safe to remove. But, I am looking forward to stripping the glue and painting it, though....
     
  6. jccabinets

    jccabinets Very well Known Member

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    Please share your painting experiments on this shell, would love to see it.
     
  7. JazzDrumGuy

    JazzDrumGuy DFO Master

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    I'm gonna try a burst by hand. Next project will be a Duco by hand.....still working out ideas......a buddy has a 90's Tama Rockstar kit in white wrap and may let me have a go at them. He is going for this look:
    download.jpeg
     
  8. loach71

    loach71 Well-Known Member

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    Cortex is vertical (postforming) grade Formica. It is a thinner version of that material used for small radius bends. It is very tough and non-permeable. The heat gun / putty knife method is the only technique with which I have had any success in the removal of Cortex from a shell. Move slowly and be patient in order to prevent any damage being inflicted on the substrate.

    Wear work gloves, long sleeved shirt, heavy work pants. Use goggles and a respirator. I prefer doing this nasty procedure outdoors....

    Good luck and be safe!
     
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  9. Hop

    Hop DFO Veteran

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    Good mention on the PPE to reduce the hazard potential.


    What are the practical methods to remove the residual glue post cortex removal... is it chemical, scraping, sanding, combo?
     
  10. JazzDrumGuy

    JazzDrumGuy DFO Master

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    Well it got done indoors, with a window open (late at night and cold!), no gloves (hence the finger got cut) and no mask/respirator/goggles. I get an F+ on safety!

    It was interesting that afterward, when I applied Citrustrip, the shell started steaming. I could not get a photo of it, but it was very odd. At that point, I did open the door for fresh air "just in case" but probably too late.

    As I was stripping last night (the drum!), I was also thinking about all the drum maker & cymbal smiths that have died early (Spizz, Skiba, Johann, Craviotto, etc.) and wondered if they died due to working in close proximity with chemicals/odors of drums/cymbals?? Hmmm.....

    Good news, other than a light cough today, an itch and watery eyes (jokes!), is that the shell was in excellent condition. I used paper towels to rub off the glue residue. I filled the bottom holes left from the concert tom metal ring and will sand the shell tonight. I may be able to start coloring tonight but not sure........
     
    Last edited: Mar 14, 2019
  11. Beefsurgeon

    Beefsurgeon Well-Known Member

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    I don't know about cymbals, but this is one of the reasons I changed careers after a decade of building drums. Despite taking the expected precautions, I'm pretty sure that continual exposure to all this stuff over time would have started to take a toll. Glass glitter dust is not good for your lungs...

    We would use a chemical to strip glue from "de-wrapped" shells. I don't remember what it was called, but that stuff was nasty. We would try to do this near the door with a fan blowing the fumes out. As I recall, the stuff would gradually dissolve your gloves, so you'd have to change them out every twenty minutes or so.
     
  12. Hop

    Hop DFO Veteran

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    WOW!

    Sounds like this stuff worked pretty well... curious as to how long you let it set - just follow the directions/recommended time, and then wipe off?
     
  13. jccabinets

    jccabinets Very well Known Member

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    Good to hear that you got the wrap off without any more than a cut finger. Can we please see a picture of the shell?
     
  14. JazzDrumGuy

    JazzDrumGuy DFO Master

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    Here is the shell during the process. I filled the bottom holes from the concert tom metal strip and will wet the shell and sand tonight. I didn't do anything with the interior which has a clear finish....maybe I'll just Murphy soap it to clean it.

    I used a heat gun over the wrap in a 5"x5" area and heated it for about 30 secs moving the gun around, then chipped as much as I could, then repeat. I applied a thin coat of Citrusstrip and let it sit about 24 hours. I scraped it using a 3" metal scraper, but some residue was left. Since the shell was still slightly damp after, so instead of a 2nd round of stripper, I just rubbed the remaining glue off using paper towels. The seam of the wood still had some glue and I tried Goo Gone but it didn't work, so I redid about a 1" wide strip x shell height of stripper and will get that off tonite. I hit it with the heat guy after to remove remaining moisture and will do that again.

    Shell has the typical small grain you'd see on a natural Ludwig finish and it's not junk wood at all to my surprise. It would look good just clear but I want to try a fade finish. I also have another 9x13, a 10x14 and a 16x16 (all 3 ply) and part of me is thinking to strip those and find a bass shell & make a matching set.

    Pics are below.....partially off, all off, with stripper on (glistening) and final bare shell.

    20190312_224910.jpg 20190312_233153.jpg 20190313_000639.jpg 20190314_001049.jpg
     
    Last edited: Mar 15, 2019
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  15. Hop

    Hop DFO Veteran

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    Nice job... Thanks for sharing the pics!!!
     
  16. JazzDrumGuy

    JazzDrumGuy DFO Master

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    I don't know the recommended time to stay on, but I've done a handful of shells and found overnight is better mostly because the glue remains damp and the remaining glue is much easier to remove once the wrap is off.
     
  17. Hop

    Hop DFO Veteran

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    I was curious how critical that soak time was... I was thinking that maybe the wood/grain might swell up too much, but that last pic shows the shell looks pretty darn good.
     
  18. loach71

    loach71 Well-Known Member

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    Many of the chemical stripping agents are based on a gelling compound and methylene chloride. The solvent, methylene chloride is very effective in the removal of paints, varnishes, glues etc. -BUT- it is very toxic and extremely injurious to the skin and eyes. Please do an internet search on methylene chloride to learn about its hazards and how to handle it and work with it in a safe fashion.
     
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  19. loach71

    loach71 Well-Known Member

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    You have done a great strip job! BTW -- you forgot to include the brass pole in your pictures... :laughing3:
     
  20. JazzDrumGuy

    JazzDrumGuy DFO Master

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    That's for VIP room gigs only.....
     
    Last edited: Mar 15, 2019
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