STS-250 - Didn't stop my water issue.

**TheShaddix** · 10-06-2014, 08:50 PM

I also tried these things and they didn't help at all. The bearings had leaking issues just as you described. Try using some heavy marine grease in combination with gear oil (grease in the drive and oil in the shaft). Ever since I started doing that the boat is always dry inside, that's at about 80-85 mph. Thing is, you have to re-grease/oil it in between every run session. Before I used to get quite a bit of water too.

**fidelity101** · 10-06-2014, 09:13 PM

Thanks for the option,what oil would you recommend? I have these options available that I picked up in Toledo...would the oil work? I'm currently using speed grease for everything.

Also, this new boat comes with a strut with a pressed bronze insert...nothing to remove. My previous UH-1 had an upgraded strut with a removable bronze insert and it never gave me any water issues. Looking the two struts, do you think one is better than the other?

IMG_2436.jpg IMG_2437.jpg IMG_2438.jpg

**Fluid** · 10-07-2014, 02:48 PM

...The problem I'm having is that after a solid 4 minute run time, I have a 1/2 cup of water in the sponsons. I decided to install the Aeromarine Laminates STS-250 in order to limit the drive shaft as a possible source of water...bad idea I guess!

Great marketing idea but it was not designed to solve the water intrusion problem.

The space between the strut and prop collar was 4mm and I reduced that space to 1/2mm...no difference in water intake....

But a big difference in driveline drag as the cable shortens and the drive dog binds against the end of the strut.

Use large silicon fuel tubing and form a gland over the inboard end of the stuffing tube. You want the fuel tubing to just touch the cable, this will seal out most all the water coming up the tube and you will not have to re-lube with thick grease after every run (unless you want to). The photo below is for a wire drive but the same idea works great for cable. If this does not solve the issue then the water is coming from someplace else.

DSC00030.jpg

For boats like this I prefer to use the perforated floating bushing like SpeedMaster (among others) uses. Less chance for water to be forced into the stuffing tube at the high pressure zone (strut nose).

.

**ron1950** · 10-07-2014, 05:09 PM

you might try heat shrink to the stuffing tube where it goes into the strut, seems to work well for me with little or no more drag

**TheShaddix** · 10-07-2014, 05:27 PM

I use royal purple (http://s7d4.scene7.com/is/image/Turn5/45018?$s7product$), anything that's heavy enough to stay inside.

For grease I use "blue-goo" from http://rcboatparts.com/supplies.html, but any heavy marine grease will be just fine as long as you re-grease often, in my case everything gets washed out after 10-15 minutes, but the hull is still 100% dry. The speed oil you got is good for bearings, not heavy enough to stop water and it'll just get messy and won't stay in. And you should add the oil at the collet side, not too much, after you grease the drive side of the tube so it stays inside. Then slide the cable in while holding your finger over the collet side exit so it doesn't push the oil out, wipe off the excess on the exposed cable and you're good to go. If you get leak issues after this, the issue has to be something else like wrong sized tubing or leaking through where the tube is epoxied to the hull. Another thing, I run my boat in salt water. So this should be even better in fresh water.

In my case, if I don't re-lube the cable/shaft in between runs, and by runs i mean when I have to re-charge the batteries, there is water in the hull every time, and quite a bit of it. Plus it's a good idea to keep it well lubed at those rpm's to reduce wear on the teflon.

As far as the silicone trick, the problem with that is it heats up eventually and can easily bind itself to the cable and get inside the stuffing tube since the cable will try to "screw" it inwards, even if the tube is barely touching. I've had this happen with 5mm tubing and burnt out a motor when the shaft just locked up at full throttle, same exact way as on the image posted above. For slower boats this will work for sure, but there is just too much friction and heat at higher rpm. Not saying it's a bad method, but it did not work for me. Also tried the heatshrink method, it works for a few runs and then the cable just tears through it. And if you're getting that much water in, this will not stop much of it as it'll build up and leak out of it anyway since there is still some gap in between. Best way is to stop the water inside of the shaft, not on the outside. I was recommended this grease/oil method by Manuel, so I trust him. Tried it once and it worked like a charm, he knows his stuff. You'll get a lot of opinions on this, but the best one will be the one that will stop your water issues.

**kfxguy** · 10-07-2014, 05:49 PM

Let me give you some info on what I've found.....

1) the sts bearing is not sealed. I just ordered some sealed bearings. You can get one for about 3 bucks.

2) the bearing just slides into the housing. It's not sealed. Little bit of Silicon or low strength loctite will fix that.

3) do you have all your cooling lines zip tied? If not, do it. I've had them seep water at high speeds.

4) I've chased my tail before to find that a seam in the Hull had a pin hole in it.

5) cooling jacket seeping?

6) I put a little silicone where the stuffing tube goes into the strut

just some ideas

**fidelity101** · 10-07-2014, 07:09 PM

Thank you for all the suggestions.

1.) The bearing in my STS-250 looks sealed. It has a metal case over the center. The water seems to be coming in from between that bearing and the housing.

2.) I used QUICK GRIP to seal the bearing to the housing. I also used QUICK GRIP to secure the second piece that attaches to the inside of the bearing. The teflon tube comes up against that second piece so hopefully having that sealed to the bearing will also help.

3.) I did a pressure test and noticed the extra large tubing (from OSE) was to big for the application. Even with the zip ties, air was leaking through when I applied pressure to the system using a syringe and blocking the outlet pipe. I replaced all tubing with large tubing (from OSE) and instead of zip ties, I just cut a piece of tubing and placed it on top of the end piece, which usually works very well in the airplane world. It provides even pressure on the end and the air seems to be holding much better.

4.) I think I may have a pin hole or two in the front section of the seams. I noticed water coming in but there is a block of wood preventing me from looking inside the front section of the hull. I'm going to use some paper toweling to see if water is still coming through and I may add some thin CA to the seam to see if I can't fill in any pin holes.

5.) cooling jacket seeping: I never thought about this as an option as it's a brand new motor and jacket, but that's a very good idea...I'll go test that this evening before the next run.

6.) I have a 1/2" gap between the stuffing tube and strut. The teflon tube connects the two and I use heat shrink tubing to seal both ends. I also used a little bit of QUICK GRIP to hopefully lock the teflon tube in place and prevent it from sliding around.

Thank you for the grease recommendations. I have so many tubes of marine grease in my inventory so hopefully I can get it to work with what I have. I have the Pro Boat Grease gun and marine grease as well as the speed grease that I OSE sells.

I also replaced the flat bottom strut with the original strut that seemed to work very well in my Joysway UH-1. It has a floating busing and it's all brand new gear so hopefully it should do the trick. Aeromarine is sending me some teflon bushings to install in the flat bottom strut previously provided with my boat so hopefully I can give those a try when they arrive and see if that helps with the water leak as well.

IMG_2398.jpg

**kfxguy** · 10-07-2014, 07:35 PM

The bearing is most definitely not sealed. I have mine apart right now to confirm. It's a little read wafer that acts as a dust seal.

Maybe mix up 30 or so grams of epoxy and pour it in and tilt the boat to let it run down. Make sure you tape up the seam on the outside or you'll get drips of epoxy. Hopefully you get it lined out!

**fidelity101** · 10-07-2014, 07:47 PM

You are correct, I though that dust shield was a seal...it's definitely not. Do you recall where you purchased the replacement bearings and what size they were?

I used that quick grip stuff which does a really good job holding my ESC inside the boat so hopefully it will be enough to prevent leaking between the bearing and the housing. I'm going to let it dry overnight and test it out the next time I can go for a run. Aeromarine is sending me a replacement bearing as the bearing is suppose to be a tight fit inside the housing where mine simply drops in and moves around inside the housing with a little bit of play. I think a tightly pressed bearing inside the housing with be better than any other option I've tried and going with a sealed ceramic bearing would be the optimal solution.

This water issue seems very strange as my Joysway UH-1 setup never had a drop of water and it ran with pretty much the same system that I'm using in the Aeromarine Conquest. It seems that every boat is different.

**kfxguy** · 10-07-2014, 07:59 PM

Originally posted by fidelity101

You are correct, I though that dust shield was a seal...it's definitely not. Do you recall where you purchased the replacement bearings and what size they were?

I used that quick grip stuff which does a really good job holding my ESC inside the boat so hopefully it will be enough to prevent leaking between the bearing and the housing. I'm going to let it dry overnight and test it out the next time I can go for a run. Aeromarine is sending me a replacement bearing as the bearing is suppose to be a tight fit inside the housing where mine simply drops in and moves around inside the housing with a little bit of play. I think a tightly pressed bearing inside the housing with be better than any other option I've tried and going with a sealed ceramic bearing would be the optimal solution.

This water issue seems very strange as my Joysway UH-1 setup never had a drop of water and it ran with pretty much the same system that I'm using in the Aeromarine Conquest. It seems that every boat is different.

This is what I bought. I bought a 4 pack to have some for other builds. I saw some non ceramic singles. Search 168 flanged bearing.....

Pardon Our Interruption...

http://www.ebay.com/itm/221311527183?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

**Peter A** · 10-07-2014, 08:18 PM

3.) I did a pressure test and noticed the extra large tubing (from OSE) was to big for the application. Even with the zip ties, air was leaking through when I applied pressure to the system using a syringe and blocking the outlet pipe. I replaced all tubing with large tubing (from OSE) and instead of zip ties, I just cut a piece of tubing and placed it on top of the end piece, which usually works very well in the airplane world. It provides even pressure on the end and the air seems to be holding much better.

An air pressure test on a water cooling system will not give you an accurate result as air will compress while water will not. Air may also leak from water seals whilst the hydraulic pressure from water may help create the seal. You will also be able to see any water leaks.

**jcald2000** · 10-08-2014, 07:54 AM

How do you seal the flex cable to the bearing??

**PowerDemon** · 10-08-2014, 08:38 AM

I agree with kfxguy on the cooling lines. I have had trouble with my cooling lines leaking badly and spraying water in the interior of the hull. All you need to do is zip tie all the cooling lines where they go into the motor or the esc.

**kfxguy** · 10-08-2014, 11:15 AM

Originally posted by jcald2000

How do you seal the flex cable to the bearing??

It has an o ring

STS-250 - Didn't stop my water issue.

STS-250 - Didn't stop my water issue.

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