how to remove bad core and delaminated fiberglass using pneumatic air hammer

[noli]

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http://www.youtube.com/watch?v=s2S4ZcMJ_GA










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[noli]

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makes the demolition job go faster





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[noli]

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you'll need 15 amp power supply, compressor and the air hammer tool





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[FUJIMO]

...air chisel...

[FUJIMO]

...those plywood cores lasted more than enough years from day one, to serve the boat manufacturers purpose, warranty & costs in building a new boat... however they now decide to replace this core material, isn't going to last forever either...

[XstreamVking]

That air hammer will crack the glass. I would NEVER do this on mine or anyone else's boat. Metal on glass is a big no-no.

[MattGreen]

A chainsaw circlet-style cutterhead (Lancelot and competitors) on an angle grinder absolutely eats wet (or dry) plywood, might be a better way and less chance of cracking as Xstream indicates.

Matt

[noli]

That air hammer will crack the glass. I would NEVER do this on mine or anyone else's boat. Metal on glass is a big no-no.
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how would you remove delaminated glass as depicted in the video?







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[XstreamVking]

I have used the lancelot chainsaw blade like described by mattgreen above. Aggressive 24# discs and plastic/wood wedges. When in the biz I built an air powered 18''chainsaw to cut out foam and wood quickly. jm2cts. Everyone does this stuff their way. Air chisels work for you go for it.

[noli]

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I'm just trying to get as many experienced systems of removing delamination for educational purposes


thanks for your input Xstream






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[XstreamVking]

There is tool called a "gellcoat peeler" mainly designed for osmostic blister repairs. Some vids on you tube of it in action. It has some use as a grinder replacement.

[MattGreen]

Hi Noli, to build on your thread, and a bit of a clarification, removing delaminated wood core is a somewhat different question than removing delaminated glass. Either or both can happen, for different reasons. Xstream is on the mark as usual with his input. Gelcoat peelers are for planing away Fiberglass laminates and gel. They have been on the market for decades and can remove lots of material, but not super accessible to DIYers. They are marketed to professional boatyards, I think a person wanting to fix their own boat would struggle to get access to one at a reasonable price.

Another option for removing lots of Fiberglass at a time that is easier to get is a segmented diamond cutter head on a big angle grinder. These are marketed for bevelling and planing concrete. I have a 7” one on a 15 amp Makita grinder with an aftermarket cast aluminum guard/dust shroud. It absolutely mows down glass, like old stringer tabbing for example. A quick pass afterwards with 24/36 grit regular grinder disc and you’re good to go.

Matt

[noli]

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Thanks Matt for the input...would a gelcoat peeler work for the same task the guy in the video was doing [ time 0:30 to 0:40 ] ?








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[noli]

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looks like Metan Marine has been using air chisel for more than a decade



http://www.youtube.com/watch?v=o7NvUVHADEw








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[XstreamVking]

Look closely at the 50 sec fwd mark. See the white marks on the green glass areas. That is where the chisel has fractured the glass. Look at the marks, same size as the chisel blade. They are in "get-er-done" mode. Not the way I did it, but if you want to make money it's the quickest way.

[XstreamVking]

In listening to the tech speak at the 1:30 mark he says epoxy. Whalers were never made with any epoxy. Rookie mistake not knowing the boats matl. composition.

[MattGreen]

Hi Noli, I suspect a gelcoat peeler is not good for removing wet wood, but I have not personally used a gelcoat peeler. As mentioned above, they are intended for planing away modest layers of gelcoat and fiberglass. The glass/rigging shop I worked at many, many years ago had one, but it was rarely used despite the fact that we did osmotic blister jobs on yachts fairly often (which is what they were marketed for). I seem to recall there were issues getting the knives setup all correctly. Our glass-prep labourer would usually just use a big grinder and regular disc.

Matt

[tnelsmn]

I wonder if the metal chisel is what caused some of the stress cracks on the bottom of mine? I know when the core was removed an air hammer was used. I've always thought it was just from the completely rotten core allowing the outer skin to flex. Now I'm thinking differently. Glad I repaired them all.

[LakeFever]

Interesting thread. Seeing as I have no idea how mine was stripped I’ll be making an extra close inspection of the hull before I begin any layup