Buying castor oil

[jimbouy]

Visited 3 local chemists today to be told they no longer stock it. One said it has been banned for internal use so they can no longer sell it.

Needed it for fitting nasa echo. any ideas or alternatives??

Jim

<hr width=100% size=1> "It is a pleasure to give advice, humiliating to need it, normal to ignore it"

 

[sailorman]

olive oyle would do

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[VicMallows]

Keep trying. Our local independent chemist still has it on the shelves. Expect some advice and/or amusement until you explain what its for! I even got some free (out of date) from a tiny chemist on the IOW when I told them it was for the echo.
In fact any oil will work. . I was told a long time ago that castor has the closest sound transmission to sea water but have no idea if that's the true reason it's used. Olive would solidify at low temperatures, etc. Water will also work fine, but of course evapourates and freezes.

Vic

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[sailorman]

my Raytheon transducer is "bonded" to the hull, they provide it in the kit.
i seem to rember that " silicone" also works

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[Talbot]

Silva will accept castor oil, but the service agents recommended that I used fresh water with anti-freeze added. If there is a spill , there is very little mess, whereas castor oil is a pig to get of the gel coat.

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[VicMallows]

Yes, I think almost any method will work as long as there're no air/bubbles between transducer and hull, as long as you're not bothered about removing it without damage. Didn't someone suggest chewing-gum (presumably chewed) a short while back?

Vic

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[yoda]

I have used sea water for over 20 years without any problems, Sea water is unlikely to freeze, is very cheap and reaaily available. try it and sea you have nothing to loose.

Yoda

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[oldharry]

Bilge water works well. One boat came into our yard this winter with a Humminbird fishfinder with its transducer simply lying in a pocket of bilge water behond a moulded frame. Worked perfectly for 2 - 3 years. The owner reckoned he had put the transducer there to see if it worked OK before glassing in, and had just forgotten about it!

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[jollyjacktar]

Figure it out, if you mounted it as a "through hull" fitting it would be in a sea water medium. Instead you intend to bounce the signal through the hull itself and presume that the skin of your boat will be invisible to the echo detection. Put it in sea water inside the hull. As someone suggested, dangle it in the bilge water.

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[Guest]

Cleaning Castor Oil is a doddle ......

As many times quoted on the forum ..... wipe away excess, spray oven cleaner liberally over it, let it fizz and bubble ..... wipe away, repeat if necessary. Finally rinse off with fresh water - clean enough to glass to !!!


<hr width=100% size=1>Nigel ...
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[Guest]

Normal Recc\'d method

It has been for years recc'd by most E/S manufacturers to use Castor OIl in the In-Hull tube - to give best signal transference to the hull and beyond.
Due to the short miniscule distance between transducer face and hull literally any liquid medium will do the job. Some have used sea-water, fresh-water, cooking-oil, and of course the recc'd Castor Oil.

It does not meen its wrong ....

I'm just trying to understand why Castor Oil is banned ?? I have heard this before - but when checking with my local chemist before - even they couldn't understand it ! I know the large bottles you used to be able to get when I was younger have been stopped years ago ..... now I get it in 250 ml 'pill bottle' size ..... enough for two filling of tube.

Of course there is another way ------- epoxy resin the tranducer to the inner-hull, with a brace across the top to stop it being broken away .....


<hr width=100% size=1>Nigel ...
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[Guest]

The sound transfer is close to the GRP - as I was told....... not water.... with Castor Oil. It does not freeze in normal conditions, is viscous and will not evaporate readily etc. etc.


<hr width=100% size=1>Nigel ...
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[Guest]

Blue-tack, Chewing gum etc.

But NOT doble sided foam tape !!!! IT has to be a materila that has no air or pockets to asborb / pevent sound pulses.

Even with Castor ..... you should wait a little while after pushing transducer into it for air bubbles to disperse .....


<hr width=100% size=1>Nigel ...
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[snowleopard]

castor oil is sold as Castrol 'R' by motor shops. it is used as a racing oil. obviously it will have a few additives so you wouldn't drink it but it should serve your purposes.

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[Guest]

Now that reminds me - as Castrol R and similar is the castor oil used in Model engines - mixed with Methanol !


<hr width=100% size=1>Nigel ...
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[jimbouy]

Thanks to all for your suggestions

<hr width=100% size=1> "It is a pleasure to give advice, humiliating to need it, normal to ignore it"

 

[VicMallows]

So that's why I could never get my little model aeroplane engine going! ... we didn't have (know about) ether when I was 10.

Vic

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[bdsweeting]

Castor Oil was also recommended for the suspension system of the Citroen 2CV. Whether that helps or not I'm not sure but if you have a local 2CV nut they might be able to point towards a supplier.


<hr width=100% size=1>Brian

 

[pentland]

http://www.rcmodelflyers.co.uk/4um/attachments//castor.jpg

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