Island Time 1,211 Posted November 5, 2021 Share Posted November 5, 2021 I need to rebuild my rudder. Who knows where I can buy some suitable closed cell pourable foam? I believe it needs to be about 16lb density, urethane. But thats from Mr Google, so any advice would be appreciated... Quote Link to post Share on other sites
slanty 8 Posted November 5, 2021 Share Posted November 5, 2021 First few mins of this might be useful. 2 Quote Link to post Share on other sites
syohana 37 Posted November 5, 2021 Share Posted November 5, 2021 NZ Fibreglass sell it: https://www.nzfibreglass.co.nz/2015/shopexd.asp?id=81 Quote Link to post Share on other sites
Island Time 1,211 Posted November 5, 2021 Author Share Posted November 5, 2021 14 hours ago, syohana said: NZ Fibreglass sell it: https://www.nzfibreglass.co.nz/2015/shopexd.asp?id=81 Yeah, saw that, but its not really dense enough to be ideal to use in a rudder. Needs to be about 16lb/ft2 or 80kg/m2... Quote Link to post Share on other sites
aardvarkash10 943 Posted November 6, 2021 Share Posted November 6, 2021 heres a local one - not sure on its density, but I'm confident you can read a product sheet https://www.norski.co.nz/collections/foams/products/norski-pour-in-foam Quote Link to post Share on other sites
Island Time 1,211 Posted November 6, 2021 Author Share Posted November 6, 2021 2 hours ago, aardvarkash10 said: heres a local one - not sure on its density, but I'm confident you can read a product sheet https://www.norski.co.nz/collections/foams/products/norski-pour-in-foam PHYSICAL FEATURES (Free Rise Foam)Density34-35kg/cubic metre 1 Quote Link to post Share on other sites
aardvarkash10 943 Posted November 6, 2021 Share Posted November 6, 2021 21 minutes ago, Island Time said: PHYSICAL FEATURES (Free Rise Foam)Density34-35kg/cubic metre chuck some filler in it - only you will know.... Quote Link to post Share on other sites
Black Panther 1,568 Posted November 6, 2021 Share Posted November 6, 2021 Is more better/ stronger? Quote Link to post Share on other sites
Island Time 1,211 Posted November 6, 2021 Author Share Posted November 6, 2021 30 minutes ago, Black Panther said: Is more better/ stronger? Yes, Higher density means harder for the frame to move thru the foam... Jeffa rudders use 90 Kg/m3 foam. The compressive strength of the foam is probably more important, so when the frame presses on the foam it does not give, but seems hardly anyone provides that.. Still researching... Quote Link to post Share on other sites
syohana 37 Posted November 6, 2021 Share Posted November 6, 2021 10 hours ago, Island Time said: Yeah, saw that, but its not really dense enough to be ideal to use in a rudder. Needs to be about 16lb/ft2 or 80kg/m2... C Did you call NZ fibreglass and ask? not everything is on their website. I expect if they can't supply it they will at least know who can. Quote Link to post Share on other sites
Island Time 1,211 Posted November 6, 2021 Author Share Posted November 6, 2021 Thanks, yes a few calls to make tomorrow! Quote Link to post Share on other sites
Island Time 1,211 Posted November 8, 2021 Author Share Posted November 8, 2021 Launched after antifouling in the weekend today. After work tonight, dropped the rudder in the berth and took to the workshop. Tomorrow i'll cut one side out and remove the foam to inspect the frame.... Quote Link to post Share on other sites
slanty 8 Posted November 8, 2021 Share Posted November 8, 2021 be great to see photos... Quote Link to post Share on other sites
LE Bb 24 Posted November 8, 2021 Share Posted November 8, 2021 If your cutting a side skin off it why don't you fit proper 80kg/m foam Quote Link to post Share on other sites
Island Time 1,211 Posted November 9, 2021 Author Share Posted November 9, 2021 I will use 80kg foam or above. Due to the nature of the internal shape, frames etc, pourable foam (urethane or Epoxy) ensures no voids, it's very difficult to get an exact match with rigid foam. The rudder is off and stripped, the internal frame tangs are broken in several places. Pics to come... 1st job has been to clean up the shaft and frames for repair... Quote Link to post Share on other sites
slanty 8 Posted November 9, 2021 Share Posted November 9, 2021 As a matter of interest, how did you know this job was due? Loss of steerage? 😉 Quote Link to post Share on other sites
Island Time 1,211 Posted November 9, 2021 Author Share Posted November 9, 2021 4 minutes ago, slanty said: As a matter of interest, how did you know this job was due? Loss of steerage? 😉 Nope, normal rudder bearing play test at antifouling time, revealed movement of shaft in rudder, not heaps, but should be none Quote Link to post Share on other sites
CarpeDiem 419 Posted November 9, 2021 Share Posted November 9, 2021 37 minutes ago, Island Time said: I will use 80kg foam or above. Due to the nature of the internal shape, frames etc, pourable foam (urethane or Epoxy) ensures no voids, it's very difficult to get an exact match with rigid foam. The rudder is off and stripped, the internal frame tangs are broken in several places. Pics to come... 1st job has been to clean up the shaft and frames for repair... Wow, those tangs were already broken?!? That didn't happen as part of disassembly? I am most impressed that you can drop your rudder in the berth. Mine would be in the mud along with every bearing. Quote Link to post Share on other sites
Island Time 1,211 Posted November 9, 2021 Author Share Posted November 9, 2021 No Roller bearings in IT, vesconite bearings, just bushes really. These ones I put in in 2002, no sign of wear yet, close on 30,000 Nm since then. Yes, the tangs (3mm or so stainless) were broken, just sent the shaft to the fabricator to replace the tangs in 6mm, and larger gussets. About $2k for the stainless work. Quote Link to post Share on other sites
Black Panther 1,568 Posted November 9, 2021 Share Posted November 9, 2021 Broken because stressed or broken because corrosion? Quote Link to post Share on other sites
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