'Re-foaming' a Rigid Raider.

Discussion in 'Engineers' Talk' started by Allsorts, Sep 24, 2018.

  1. Allsorts

    Allsorts Well-Known Member

    And now for something completely different.

    We (the SC) have an 18' Rigid Raider as one of our boats. The hull was originally foam-filled which made it unsinkable, but this was cleaned out a good number of years ago when the boat was overhauled.

    We'd like to refill it.

    I guess I should ask on specific forums, but does anyone on here know of a good quality and fully waterproof expanding foam product that could be used? It would almost certainly have to be a two-part product so it 'cures' and not just set by evaporating vapours.

    Any ideas?
  2. joinerjohn1

    joinerjohn1 Screwfix Select

    Not sure that overhauling a boat would include removing the material that helps keep it afloat DA. I reckon you’ve been done. Might be an idea to get in touch with the manufacturers BAE Systems for advice ?
    Allsorts likes this.
  3. Isitreally

    Isitreally Well-Known Member

  4. Allsorts

    Allsorts Well-Known Member

    The boat's been there a lot longer than me, and originally did have the foam in it. A good number of years back it was given a major refurb which involved splitting the hull from the deck. Someone then made the (silly in retrospect) judgement to remove all the damp foam and try and make the hull fully water and air tight when the deck was put back on.

    Needless to say, making such a large section with awkward joints completely air tight was a near impossibility and we soon found water gathering in there. Next solution was to leave the hull's drain plug open (it drains in to the bilge recess at the back of the boat), but this then has the effect of allowing water in there whenever it rains.

    So each wee trip begins with some serious bilging...

    We are now reassessing the whole caboodle, and my feeling it that it should be re-foamed up to at least the draft line.

    That looks like ideal stuff, IIR - thank you.
  5. Richard_

    Richard_ Active Member

    I'm not sure what your boat looks like. The rigid raider pictures online are open metal tubs with floatation compartments (benches) under the thwarts. So where is the deck ?

    Could you get bladders in there? Although you'd need to regularly check they are inflated whereas foam doesn't need checking.

    In terms of buoyancy, these compartments don't do anything until you capsize or when the boat is swamped. So they only need to trap enough air to keep the thwart above the water while you bale it out.
  6. Pollowick

    Pollowick Well-Known Member

    I have dealt with CFS - good company to deal with who know their stuff. They will be a great source of advice and materials - I buy acetone, meths (without the purple dye), isopropanol &c from them and service is great.
    Allsorts and KIAB like this.
  7. sospan

    sospan Well-Known Member

    Going to need a fair old engine to get that moving
  8. HarDeBloodyHarHar

    HarDeBloodyHarHar Active Member

    I thought they just used large inflatable bags(bladders) instead of foam for that nowadays.
  9. sospan

    sospan Well-Known Member

    Its old and ex -mod. The problems with inflatables bags are - bullets :D
    Allsorts likes this.
  10. Allsorts

    Allsorts Well-Known Member

    All fibreglass. Cathedral hull. They are absolutely brilliant - gets up on the plane easily, and turns on a half-pence. Stable, large flat deck - just superb boats.

    We have a brand new 50HP Evinrude on it which gets it up to around 20 knots or so - that's enough. Would you believe that the new engine is 2-stroke? And has fewer nasty emissions than a 4 stroke - they claim.

    Looks like: $_86.JPG

    We want to fill the whole (or most) of the hull, not only for safety but also to stop the bludy water getting in to the empty hull area which is sealed off apart from a wee drain at the back.

    IIR's CFS links looks ideal - thank you all.
  11. sospan

    sospan Well-Known Member

    Last one one those i went on, was on the Thames with what can best be described as being driven by a bunch of hooligans equipped with what felt like an F1 engine. Oh yes they take to the air quite easily as they were keen to show, especially if you cut across another boats wake. Got off feeling like I had been hit all over with an iron bar. :oops:
    Allsorts likes this.
  12. Richard_

    Richard_ Active Member

    The foam in the CFS link would mean cutting holes in the thwarts for pouring the stuff in. Injectable foam might be easier with fewer smaller holes to cut and repair?
  13. fillyboy

    fillyboy Well-Known Member

    I was under the impression that 2 stroke outboards for recreational use were banned some years back by the EU, how did you get around it?, Chinese import?
  14. HarDeBloodyHarHar

    HarDeBloodyHarHar Active Member

    Banned by the EU? Here we go.......
  15. Allsorts

    Allsorts Well-Known Member

    Possibly, but larger access holes - with screw-down lids - would also allow for inspection.

    Anyhoo, I'll just be taking ideas to a meeting at some point, so thanks for all the contributions, folks :)
  16. Allsorts

    Allsorts Well-Known Member

    Yeah, I thought that too - I didn't believe it when the guy in charge of the boats told me it was a 2-er. Seems it actually has less harmful emissions than a 4-stroke. Go figure - I can't.

    But it is a sweeeet engine.

    It's one of them:
  17. Richard_

    Richard_ Active Member

  18. Richard_

    Richard_ Active Member

    That's do work well, just like the inspection hatches on bigger ships. Nice 200 square plates with rounded corners, counter sunk bolts and bedded on a bead of silicon. It's tempting to bolt those on even if you don't cut the holes!
  19. Allsorts

    Allsorts Well-Known Member

    Square plates?! Jeepers, I was thinking more of 4" plastic screw-down covers :)

    Hole-saw, screw down, jobbie jobbed.
  20. HarDeBloodyHarHar

    HarDeBloodyHarHar Active Member

    And you wonder why ya boat leaks!

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