Topic: Need Gasket for my Robbe Sea Wolf V2 (Read 7942 times)

David_l_perry · « **on:** January 16, 2016, 06:34:00 pm »

Any body know where I can get a replacement large O ring gasket for the Robbe Sea Wolfe.

I have just brought it out of retirement and the original one has perished.....

Its approx 4" or 100mm dia

Thanks chaps

essex2visuvesi · « **Reply #1 on:** January 16, 2016, 06:37:19 pm »

Pm me your address I have at least one of them. I upgraded mine to bayonet fittings.

David_l_perry · « **Reply #2 on:** January 18, 2016, 08:39:13 am »

pm Sent thanks

I have also just ordered a couple of different sizes off ebay (95mm and 100mm - 3mm and 5mm) that I think will be right, so if you dont find them, hopefully I will still be sorted

Dave

Subculture · « **Reply #3 on:** January 18, 2016, 10:36:00 pm »

Something to be mindful of with these boats. The original o-ring is a special soft compound, if you use normal nitrile o-rings, you'll find they're stiffer and you may experience leaks.

Silicone o-rings are softer, and would probably do the job. They should also last a long time as silicone tends to be very resistant to ozone.

David_l_perry · « **Reply #4 on:** January 18, 2016, 10:45:47 pm »

Thanks for that - will check it out carefully in the domestic test tank.....

Is it sensible to add a bit of wax or greese or Vaseline to aid sealing....

salmon · « **Reply #5 on:** January 19, 2016, 05:20:00 am »

Quote from: Subculture on January 18, 2016, 10:36:00 pm

Silicone o-rings are softer, and would probably do the job. They should also last a long time as silicone tends to be very resistant to ozone.

I will also add to what Andy said, be careful what you use as a lubricant. If you use silicon, do not use silicon lubricant. The same is said for petroleum o-rings, you should not use petroleum products on them. Silicon o-ring with petroleum lubricant = good, petroleum o-rings with silicon lubrication = good same type of o-ring with same type of lubricant = bad
Some use vegetable oils as a lubricant, and you are pretty safe with that. I have used that because I would think it would tend to gunk up.

derekwarner · « **Reply #6 on:** January 19, 2016, 05:58:36 am »

Guys.... a few misnomers here

Silicon [MQV nomination] o-ring standard is 70 Shore A hardness
Nitrile [NBR nomination] o-ring has standard hardness's of both 70 and 90 Shore A

Naturally N7 [Shore 70 A] hardness would be preferable........ the larger the o-ring section, the larger the force to compress

that same diameter

A simple petroleum jelly would also be to totally suitable with either elastomers .............. Derek

Subculture · « **Reply #7 on:** January 19, 2016, 08:57:01 am »

A lot of nitrile o-rings tend to be 80 shore, and the material just seems tó eb slightly less compliant than silicone. There are also special o-rings in very soft compounds typically 50 shore or thereabouts, but they're a bit difficult to find. Norbert Bruggen supplies a limited range of sizes in the very soft compounds. Part of the problem with the Robbe boats is that all the compression is done with a single bolt on the end of a plastic tray.

Fitting a bayonet ring or modifying the endcap for radial seal compression is a very worthwhile modification on these boats. Always surprised Robbe didn't do this from the factory.

David_l_perry · « **Reply #8 on:** January 19, 2016, 12:46:05 pm »

Thanks for all the info guys. I never had any issues so far with the sub letting any water in, but to be fair, its only been in the water a handful of times.

I am intrigued in what modifications are involved for the 'bayonet fitting' ??

Any links on what this is as I cant work it out, and could not find anything on the search

Thanks

Dave

essex2visuvesi · « **Reply #9 on:** January 19, 2016, 12:52:21 pm »

I have the piranha modelbau one and its pretty straightforward, if a little time consuming

Retrofitting would be a pain as you will need to remove the rails in the WTC
The WTC will need to be cut down by about 12mm
you also need to shave a few mm off either side of the tech rack as the Bayonet has a lip on the inside

The Norbert Bruggen one I believe is butt jointed so would need less work

Here's mine
http://www.modelboatmayhem.co.uk/forum/index.php/topic,40289.0.html

Subculture · « **Reply #10 on:** January 19, 2016, 02:28:59 pm »

It's difficult to modify the U47 once built up, because the tech rack gets in the way. Also i think you may need to shorten the tube a bit. All rather difficult to do without causing damage to other parts of the boat, as the tube is fitted into the hull and forms a backbone for the rest of the structure, much like the 1:1 scale boat. Clever bit of engineering by Robbe, as the vacformed structure would be very delicate without that support.

David_l_perry · « **Reply #11 on:** January 23, 2016, 06:03:49 pm »

OK chaps....rubber ring arrived and fairly decent seal, but a little bit of water ingress as expected.

To be honest it could have been through the prop shaft, it was not a lot after being sat in the bath for an hour...just enough to wet a bit of kitchen towel I put in as a telltale

So this got me thinking about making the change to the bayonet connection.

I'm a little unclear on what exactly changes on this. Is the bayonet simply the seal, and does the tray still get pulled in with the front threaded section ?

Or is the bayonet also the locking mechanism, so that the front bolt and hole is then omitted...

Could not quite make it out from what I have seen

Also, could not find the link for the actual bayonet part for the Robbe Sea Wolf - so any links or advice.

Thanks

Dave

essex2visuvesi · « **Reply #12 on:** January 23, 2016, 06:41:36 pm »

These are the 2 bayonet kits that I know of:-

Norbert Bruggen:-
http://www.modelluboot.de/Zubehoer/Bajonettver.html

Pirana:-
http://www.piranha-modellbau.de/Preisliste.htm

Subculture · « **Reply #13 on:** January 23, 2016, 10:04:14 pm »

Norbert's link is saying the Robbe bayonet ring is no longer available. The piranha link says just 1 in stock. If you going for that option you ought to be quick, I expect the lack of stock is due to these kits now being out of production, so once they're gone, they're probably almost certain going to be unavailable.

essex2visuvesi · « **Reply #14 on:** January 23, 2016, 10:15:33 pm »

I'm working over the weekend but when I get chance I'll post up whats needed to upgrade to the bayonet fitting

David_l_perry · « **Reply #15 on:** January 24, 2016, 08:04:35 pm »

Thanks Chaps

Have emailed Piranha to check its in stock.

I am still unclear if the bayonet acts as the locking and sealing mechanism in one ?

essex2visuvesi · « **Reply #16 on:** January 24, 2016, 08:41:42 pm »

Quote from: David_l_perry on January 24, 2016, 08:04:35 pm

I am still unclear if the bayonet acts as the locking and sealing mechanism in one ?

Yes it does,
The front screw becomes redundant

I epoxied a suitable sized nut and bolt into the hole in the front endcap

Also a top tip.... when the bayonet arrives, dont try putting it together to "see how it fits" It's a tight fit and a sod to get apart again. (Ask me how I know

)

David_l_perry · « **Reply #17 on:** January 24, 2016, 08:56:52 pm »

Fantastic - that's more than convinced me to make the change.

essex2visuvesi · « **Reply #18 on:** January 24, 2016, 10:29:02 pm »

It's a little fiddly to do after the event but perfectly feasible

I have a couple of days off this week so I'm planning on some "shed time"

I'll get some pics of the modifications

You'll have to excuse the state of my tech rack.... its been modded too many times, so I'm in the process building a replacement

David_l_perry · « **Reply #19 on:** February 11, 2016, 07:03:30 pm »

Well....not had any response whatsoever from Piranha......

Any other suggestions on where to get a bayonet fitting from ???

essex2visuvesi · « **Reply #20 on:** February 11, 2016, 07:23:50 pm »

Quote from: David_l_perry on February 11, 2016, 07:03:30 pm

Well....not had any response whatsoever from Piranha......

Any other suggestions on where to get a bayonet fitting from ???

Did you contact Norbert Bruggen?

David_l_perry · « **Reply #21 on:** February 11, 2016, 07:29:08 pm »

Its listed as no longer available on the web site.

essex2visuvesi · « **Reply #22 on:** February 11, 2016, 08:30:12 pm »

Quote from: David_l_perry on February 11, 2016, 07:29:08 pm

Its listed as no longer available on the web site.

Might still be worth giving him a shout, as he might be able to source one for you

David_l_perry · « **Reply #23 on:** February 12, 2016, 07:59:26 am »

Yep, will ger in touch with them

David_l_perry · « **Reply #24 on:** February 12, 2016, 08:58:40 am »

Emailed both now....English and German translations, so hopefully will get something back -Failing that I will carry on using the O rings until I can source an alternative

I do have access to CNC facilities so perhaps I will look at getting one fabricated if I cant source one...

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Author Topic: Need Gasket for my Robbe Sea Wolf V2 (Read 7942 times)