Repairing holes in fibreglass roof

Discussion in 'Mech Tech' started by Jonboy_t, Jun 14, 2019.

  1. I’m planning on removing the pop top after we’ve been away in July and doing an overhaul on it (rear hinged westie). The bolt holes that connect it to the rear hinge have all pulled through the fibreglass due to bent hinges, so will need to fill them all and redrill the holes.

    Any tips on best compound to use? I’m repainting the whole thing so colour match isn’t an issue. Was wondering if some sort of epoxy might be stronger than just a fibreglass repair kit. Also, could knock up a strip of alloy/stainless to run between all 3 bolts and the roof to spread the load - worthwhile, or overkill?
     
  2. Hi there post a pic and I can perhaps give some better advice, we manufacture and supply fibreglass, I don't think a filler will do the job as it will stress crack without a reinforcement

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  3. PIE

    PIE

    Im working on an ancient memory here but I think there may be a strip of wood in there that may be rotten due to water ingress
     
  4. Yeah, there is a strip of wood all the way down both sides and (I think) the back. Will be replacing this at the same time too.

    Will try and grab a photo, I’m away at the moment so will grab one when I get back.

    Cheers
     
  5. This is the side that’s pulled through

    [​IMG]

    This side hasn’t!

    [​IMG]


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  6. PIE

    PIE

    Im pretty sure the wood is encapsulated
     
  7. My early westy is similar- I’ll watch this with interest. I wondered about a strip of steel on top of roof - maybe stainless for some rust free bling. But for now it is ratchet strapped down as it was lifting up at motorway speeds!!!
     
  8. PIE

    PIE

    I woud think you would need some shape on the metal to keep it rigid, would some ally angle, quite long under the roof do the job?
     
  9. When I did mine the wood just fell out it was so rotten. I replaced it with ash hardwood.
    The fiberglass that should cover the wood had cracked and came away I assumed because the wood had rotted from the inside out.

    I cleaned all the mounting holes and the areas where I needed to fit the new wood i got some proper fiberglass sheeting from a guy who makes motorbike parts new mudgards ect.
    I then just started to rebuild it one sheet at a time, use proper boat building sheeting if you can and the proper hardeners it a messy job and stinks.
    Don't use filler to seal holes use fiberglass you can cut it to any size at one point I was even cutting it into tint bits and mixing it to form a paste type mixture. I also dug the cracks out to solid fiberglass it's a bit daunting but all repairable.
    You can sand fiberglass to a better finnish than filler anyway. I then painted my top with 2k paint and high build primers 3 years on and nothing has cracked.
    If your taking the rack off remove the metal rails and put extra patches of sheeting on the underside of the bolt holes then re drill the holes with a step drill not a hss speed bit as it's a better cut with a step drill.
    Look on YouTube for fiber boat repairs if it's good enough for boats it's fine for a pop top.
    Hard plastic or rubber washers for the bolts after to try and stop water ingress
     
    Aang and PIE like this.
  10. PIE

    PIE

    I think I would seat the bolts and washers with CT1 clear and I would replace the original type bolts with stainless items with a button Hex head
     
    nell likes this.
  11. I’m not sure ours is original wood, doesn’t look to be encapsulated in anything. Maybe it happened to previous owner and they did something with it?

    Here’s the inside where it’s pulled through.
    [​IMG]

    Here’s down the length of it, it’s the same both sides.

    [​IMG]


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  12. PIE

    PIE

    I think thats the wood strip that holds the canvas on, its screwed to the encapsulated one
     
  13. I’m probably missing something, but there doesn’t look to be anything other than wood all the way up to the fibreglass top - even from the outside. The rear is different, looks coated in something (presumably fibreglass), butvthe rest is just bare wood
     
  14. If I remember you have a wooden strip tack for the canvas 20mmx20mm?
    Then a fatter one for the bolts to tread into the metal hinges
     
  15. Now I'm not sure lol
     
  16. Definitely not encapsulated in fibreglass down the sides on mine, just painted wood! You can see the grain on it up close!

    [​IMG]


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    Aang likes this.
  17. If you want you can use epoxy resin but then you have to use woven fibreglass cloth or tape as the chopped strand mat is tacked together with stuff that doesnt dissolve in epoxy resin like it does in polyester.
    The benefit is that epoxy sticks better to old polyester resin than new polyester resin sticks to old.
    Epoxy glue also sticks better to wood than polyester resin.
    But it costs more so its your choice.
    Also consider the boatbuilders trick of drilling a bigger hole in the wood backing, filling that with filler and then drilling through the filler for the bolts. The filler takes the compression better than wood.
     
    Aang and Jonboy_t like this.
  18. PIE

    PIE

    That should make the job easier
     
    Jonboy_t likes this.
  19. Just looked mine should be bare but it's bonded both sides and bare wood on the bottom
     
  20. Jonboy_t and Valveandy like this.

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