Fibreglass/foam/plywood box

Discussion in 'Fiberglass and Composite Boat Building' started by Gandalftheblack, May 16, 2020.

  1. Gandalftheblack
    Joined: May 2020
    Posts: 6
    Likes: 0, Points: 1
    Location: england

    Gandalftheblack Junior Member

    Hi guys

    I am restoring a camper box for a unimog truck and I thought this place would be best to ask for advice as it uses a lot of the same materials as many boats.

    The plywood on the inside that is stuck to the foam is pretty much fused together and I found it very difficult to ply off without damaging the foam.

    The plywood is pretty thin - 3mm or something.

    So I resorted to using an angle grinder with a sandpaper disc and a belt sander.

    The wood is covered in mould and is pretty rotten in places, it kicks up a horrific stink when sanding - kind of sweet fungi kinda smell.

    My question is - is this a wise way to proceed in removing the plywood? I am using a mask and a shop vac to keep the dust exposure to a minimum; but the smell does kinda make me worry i'm breathing in something kinda nasty from the glues or something.

    Any thoughts?
     
  2. Gandalftheblack
    Joined: May 2020
    Posts: 6
    Likes: 0, Points: 1
    Location: england

    Gandalftheblack Junior Member

    Here is a photo
     

    Attached Files:

  3. Mr Efficiency
    Joined: Oct 2010
    Posts: 8,385
    Likes: 454, Points: 83, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    So what is this ply, the inner lining of the van, and the foam is insulation ? Why do you need to remove the lining, if it is stuck down well ?
     
  4. Gandalftheblack
    Joined: May 2020
    Posts: 6
    Likes: 0, Points: 1
    Location: england

    Gandalftheblack Junior Member

    Yes it’s a kind of softwood plywood. It is quite rotten and full of mold. I would rather remove it completely so there is no source of mold.
     
  5. fallguy
    Joined: Dec 2016
    Posts: 2,837
    Likes: 295, Points: 83, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    I have done it.

    oscillating tool is the only way my friend...

    best of luck; it isn't much fun, the oscillating tool with a carbide blade can lay flat and glide along the glass

    a chisel can gouge the glass

    The wood is 1/8" luan.
     
    Barry likes this.
  6. fallguy
    Joined: Dec 2016
    Posts: 2,837
    Likes: 295, Points: 83, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    The black mold can get into your lungs and cause trouble. Smelling it is bad. Run a fan across the work.
     
  7. Gandalftheblack
    Joined: May 2020
    Posts: 6
    Likes: 0, Points: 1
    Location: england

    Gandalftheblack Junior Member

    Glass?
     
  8. fallguy
    Joined: Dec 2016
    Posts: 2,837
    Likes: 295, Points: 83, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Mine was fiberglass exterior with a luan core.
     
  9. fallguy
    Joined: Dec 2016
    Posts: 2,837
    Likes: 295, Points: 83, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Yours is luan and foam? Are you just on the interior?

    I'd still use an oscillating tool.

    lots of control over depth and angles of cut
     
  10. Gandalftheblack
    Joined: May 2020
    Posts: 6
    Likes: 0, Points: 1
    Location: england

    Gandalftheblack Junior Member

    Ahh I see. Yes it is the same except with foam between. Thanks for the suggestion, I will see if I can borrow an oscillating tool. I was using a grinder but this is quite time extensive.

    I’m mainly worried about poisoning myself from the glues in the Luan.
     
  11. Rumars
    Joined: Mar 2013
    Posts: 537
    Likes: 181, Points: 43, Legacy Rep: 39
    Location: Germany

    Rumars Senior Member

    Just rip the plywood off with a crowbar, and do not worry about the foam. You will have to remove the foam anyway, it is full of mold spores and rot bacteria. When you get to clean metal (or whatever the exterior is made ot of) you clean it with a sander and glue in new foam.
     
  12. Gandalftheblack
    Joined: May 2020
    Posts: 6
    Likes: 0, Points: 1
    Location: england

    Gandalftheblack Junior Member

    It is a polyurethane foam (styrofoam) that is bonded to the exterior fibreglass. It essentially makes up the whole structure as it is a composite construction. This would be impossible. The foam is fine underneath and is not permeable.
     
  13. Rumars
    Joined: Mar 2013
    Posts: 537
    Likes: 181, Points: 43, Legacy Rep: 39
    Location: Germany

    Rumars Senior Member

    Of course it is possible. Just cut the foam out and reglue new foam in with epoxy.
     
  14. Mr Efficiency
    Joined: Oct 2010
    Posts: 8,385
    Likes: 454, Points: 83, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    Easy to say, more difficult to do, applies to many things in life. I would leave the foam alone, other than when you have removed the rotten lining, ensure it is dry, before re-lining. You may need to install a strong fan to blow air through the box, to dry it, I doubt it will dry out too readily over there in Old Blighty, even though summer is coming !
     

  15. kapnD
    Joined: Jan 2003
    Posts: 623
    Likes: 69, Points: 28, Legacy Rep: 40
    Location: hawaii, usa

    kapnD Senior Member

    I’d cut the plywood into thin strips with a circular saw, set the blade to just the thickness of the wood.
    This should make it easier to peel off with the multi tool.
    There are scraper blades available for that, as well as for reciprocating saws.
    Treat the foam for mold/mildew and dry it out well before applying new plywood.
     
Loading...
Similar Threads
  1. dantesta
    Replies:
    11
    Views:
    5,831
  2. BrissoDamo
    Replies:
    22
    Views:
    713
  3. RSD1
    Replies:
    31
    Views:
    1,108
  4. JohnMarc
    Replies:
    24
    Views:
    1,346
  5. Reefrunner
    Replies:
    22
    Views:
    1,166
  6. scottm1976
    Replies:
    13
    Views:
    1,001
  7. Quinnhp
    Replies:
    35
    Views:
    2,590
  8. mike marchetti
    Replies:
    29
    Views:
    2,335
  9. Carpenter Matt
    Replies:
    15
    Views:
    3,441
  10. Andrew Waddington
    Replies:
    6
    Views:
    5,044
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.