I learned a valubale lesson in flotation today...

[fweasel]

Proboat Impulse 31 V3. Now you see it, now you don't


https://www.youtube.com/watch?v=FCic2BIn_qY&feature=youtu.be

I'm not sure what caused it to hook suddenly and nose in. It's a very soupy mud and silt bottom. I believe the boat augured in and when the mud finally released it, the damaged hull collapsed which sent up an eruption of large air bubbles about 2 minutes later. Had I simply just lost the hatch, that would have surfaced on its own. I'm not too concerned with loosing the boat, but am bummed about the GPS, 2 Revo batteries, and a Dasboata prop. If I'm going to loose that much all at once, I want spectacular aerobatics, debris fields, public property damage liability issues, wildlife endangerment, and a burning oil slick on the surface of the water. All I got was bubbles.

In case anyone wants to go dive for it, it's right here...

153653

[boatsrnew2me]

i had read that this boat can do that ,but thats the first i seen it . has it surfaced yet?

[rol243]

r/c electric boats should always have the cowl / lid taped down not just clipped on so when your flip it upside down it just fills with water and ruins the electronics. tape the lid and gain bouyancy plus save your electronics.

[fweasel]

i had read that this boat can do that ,but thats the first i seen it . has it surfaced yet?Nope, we were there a solid hour after that running two other boats. It's gone.


r/c electric boats should always have the cowl / lid taped down not just clipped on so when your flip it upside down it just fills with water and ruins the electronics. tape the lid and gain bouyancy plus save your electronics.The hatch was securely taped down.

[rol243]

when the hatch is fully sealed there is a large amount of air inside that acts as good bouyancy but if there is a leak in the seal theres no bouyancy left.

[fweasel]

when the hatch is fully sealed there is a large amount of air inside that acts as good bouyancy but if there is a leak in the seal theres no bouyancy left.

In my original post, I mentioned a large eruption of air bubbles about two minutes later which is when I suspect the boat was released from the mud exposing a catastrophic hull issue, and imploding.

[TRUCKPULL]

A few years ago at one of the big races, we had a boat do that. Everyone thought it was gone after about 5 min.
The next day during a race, the CD yells "Dead Boat in turn 3"
Well with 5 drivers on the stand and 5 boats still racing, we all said "WHAT"
It was the boat that went down the day before, It was over 10 ft. deep in the section of the pond.

When you saw the large eruption of air bubbles, was there a little bit of white smoke with it??
I have seen this happen from batteries under water.

Larry

[MADRCER]

Man that's horrible! I had my Impulse 31 do nearly the exact same but I got it back with just the hatch cover blown apart by the impact. My GPS flew out of the boat also and was never recovered. That's where I got the idea of the little black duffel bag zip tied to the inside of boat. By the way I didn't keep that boat much longer after that either. Man I hate that feeling...

[Doby]

A few years ago at one of the big races, we had a boat do that. Everyone thought it was gone after about 5 min.
The next day during a race, the CD yells "Dead Boat in turn 3"
Well with 5 drivers on the stand and 5 boats still racing, we all said "WHAT"
It was the boat that went down the day before, It was over 10 ft. deep in the section of the pond.

When you saw the large eruption of air bubbles, was there a little bit of white smoke with it??
I have seen this happen from batteries under water.

Larry

That was Jays P Mono...I remember that race....water did get in the hull but he had enough flotation that when the mud let it go..up it went.

[Peter A]

Pool noodles, as much as can be fit, displaces water and provides bouyancy.

[rol243]

yes never go boating without adding floatation. this is lesson number one in the r/c boating industry. i remember some years back where this new guy and a brand new glow powered cat hull all worth about $2000 flipped the hull and within 30 secounds it started to go down . its still submerged in the same spot it went down in approx 20 meters of merky water, a diver couldn,t see it due to the merk.

[Insanity Plea]

I'm not sure the hull would actually implode. I don't know the depth of the water but imploding is caused by the surrounding pressure which increases with depth and causes it be crushed like a soda can. It's quite possible that it became dislodge from the mud with hull damage and all the air escaped before the boat could reach the surface.
A GoPro case can reach 200ft before showing signs of fatigue from the pressure. A cheap plastic water bottle starts imploding around 20ft and will be flat at 75ft.

[fweasel]

Based on the short duration and quantity of air released, I suspect it was all released at once. That's what I meant by implode, not purely a pressure related breach based on depth.

[rol243]

when you look close at the video , the boat suddenly flips and very slowly sinks. it doesn,t spear under the water atall. thats how it looks to me anyway.

[fweasel]

We had a good clear shot of it when it happened, it was there one second and gone the next. There was no sinking.

[kfxguy]

Whew. I thought you sank the mini Rivercat for a second there. I started to get sink lol. I'd hope it wouldn't sink. I don't think the hatch would come off no matter what and there's foam where foam will fit. Sorry for your loss but try to add more floatation in all your boats. If the hatch comes off, that's a big problem however, pool noodles will come out unless they are stuffed in there tight. A good idea is to get some of that black pipe insulation and put that on top of the batteries before you put the hatch on.

[rol243]

are there any crocks or sharks in that water, looks like something grabbed it. sorry but i had to.

[fweasel]

Ha, a large predator would be a good story, but not many of those in Chicago.

Travis, the mini is safe, still on the shelf with the shootout injuries. New rudder should be here later this week.

[Bp9145]

are there any crocks or sharks in that water, looks like something grabbed it. sorry but i had to.

I have a couple of gators in my backyard pond but not big enough to concern me. . .not yet. I go in the water too when I run my boats and have occasionally retrieved my boat by wading in the water. . .chest high. It was when I had a boat starting to sink on the deep end that I was worried because I didn't know what was beneath me. . .scary and will never do it again.

[JestDanny]

I'm guessing a turtle, do you have red ear sliders up there? #2 Carp any big carp in that pond? :noidea:

[rol243]

i did have an issue once where my boat hit something in nice clean water , there were no logs or anything floating in this small lake but when i brought the boat into shore i noticed the rudder was slightly tilted up and the prop had a mark on it, this was a new polished prop and the rudder had a saver on it so there must have been some type of fish / turtle or whatever in this fresh water that my boat hit.

[Shooter]

A few years ago at one of the big races, we had a boat do that. Everyone thought it was gone after about 5 min.
The next day during a race, the CD yells "Dead Boat in turn 3"
Well with 5 drivers on the stand and 5 boats still racing, we all said "WHAT"
It was the boat that went down the day before, It was over 10 ft. deep in the section of the pond.

When you saw the large eruption of air bubbles, was there a little bit of white smoke with it??
I have seen this happen from batteries under water.

Larry

I remember that as well. It was nothing short of incredible.

[Hydrocarbon82]

My old Shockwave 26 did a similar act and I also got it on vid. However you could see the very long but low waves it lifted off of. In my case it turned a bit and ripped the hatch off so it didn't spear the bottom.

If you slow your vid down, you can see it seems to hit an invisible wave. The bow angles up a bit, then the stern does the same and rotates the bow down. Muck is incredibly powerful so it's possible the hatch was partially covered in it, then finally released. I'd bet if you found it by dragging an anchor, the flotation inside may be enough to raise it if disturbed.

[lt130th]

This is the reason I now fill the bow of all my hulls with two-part expanding foam.

1.) Added flotation.
2.) Structural rigidity.
3.) Reduces the interior air cavity and lessens the chances of blowing out a seam when hitting the surface, after going airborne.

[CraigP]

Has anyone tried that insulation foam in a can you spray into crevices? I'm a bit concerned about that expanding foam stressing the seams on the hull... But it does have excellent flotation properties and it won't break free, unlike a pool noodle...

[kfxguy]

Has anyone tried that insulation foam in a can you spray into crevices? I'm a bit concerned about that expanding foam stressing the seams on the hull... But it does have excellent flotation properties and it won't break free, unlike a pool noodle...

Yes. Do not use that. It utilizes oxygen to cure and it takes a very long time for the center to cure resulting in a very deformed hull when it expands. I know this from experience, ruined a hull once. I also did testing by doing a small amount at a time. Still does not work. Composite envisions on eBay sells two part foam which cures from a chemical reaction instead of an oxygen reaction. HOWEVER, it will suck a hull inwards if you left it rise from bottom to top. You have to leave a gap or some way to let the foam release. Maybe put a carefully cut wax paper or maybe a plastic bag.

[CraigP]

Thanks Travis, that was my concern...

[Doby]

Has anyone tried that insulation foam in a can you spray into crevices? I'm a bit concerned about that expanding foam stressing the seams on the hull... But it does have excellent flotation properties and it won't break free, unlike a pool noodle...

It can be used safely if you know what you are doing...

1) DO NOT FILL AN ENTIRE EMPTY PORTION OF A HULL ALL AT ONCE. THE MIDDLE WILL NEVER DRY...this is where most people screw up and bitch about the product being garbage.
2) Add about a softball size blob of the foam and let it cure/expand for a day....repeat as often as needed to fill the desired void..be patient..don't rush..if it takes a week or so to do a large void..then so be it.
3) That's all there is to it.

I currently have 15 FE boats done this way, from P spec to 10S boats (as well as another 20 or so over the years) with NO issues whatsoever. It makes a flimsy hull rock solid and makes a strong hull almost indestructible. It does NOT absorb water as many claim, even if the hard shell has been cut open. Take a bite of an Aero chocolate bar and see what I mean if you don't believe me.

It does discolor a bit when exposed to sunlight...oh well.

[urbs00007]

It can be used safely if you know what you are doing...

1) DO NOT FILL AN ENTIRE EMPTY PORTION OF A HULL ALL AT ONCE. THE MIDDLE WILL NEVER DRY...this is where most people screw up and bitch about the product being garbage.
2) Add about a softball size blob of the foam and let it cure/expand for a day....repeat as often as needed to fill the desired void..be patient..don't rush..if it takes a week or so to do a large void..then so be it.
3) That's all there is to it.

I currently have 15 FE boats done this way, from P spec to 10S boats (as well as another 20 or so over the years) with NO issues whatsoever. It makes a flimsy hull rock solid and makes a strong hull almost indestructible. It does NOT absorb water as many claim, even if the hard shell has been cut open. Take a bite of an Aero chocolate bar and see what I mean if you don't believe me.

It does discolor a bit when exposed to sunlight...oh well.

exactly what foam in a can are you talking about? I have some 4 lb density 2 part foam. will that work?

[Doby]

exactly what foam in a can are you talking about? I have some 4 lb density 2 part foam. will that work?


This has been my product of choice for the past 5 years...

http://www.touch-n-foam.com/maxfill.html

Before that it was Great Stuff low expansion.

I've heard that the two part foam expands quickly so be careful...I've never had a chance to try it.

[rol243]

jusr remember that most of the aerosol can spray foam that expandes when curing is not light, it can end up quite heavy. whats wrong with pool noodles.? cut to size and pop them in the hull.

[Doby]

Not heavy at all...another misconception..

No difference between the weight of adding pool noodles.

Nothing wrong with pool noodles...whatever floats your boat.

Saw a nitro boat get T boned by another....the boat was basically cut in half...pool noodles made it safely to shore after popping out of the hull.

[CraigP]

That's my concern, if the hull breaks and the noodles just come out. I just don't want to pop my boat seams with expanding spray foam... I gotta do some test sprays and get some experience before I decide. I appreciate all the views, food for thought!

[rol243]

you only need some stick on Velcro or a bit of Silicon to hold the noodles in the hull. i don,t like the idea of that messy spray foam and what i have seen with this stuff is it has got some weight when its cured. a 4 foot noodle weights next to nothing and its available in several different colours that can suit your hull colour.

[kfxguy]

That's my concern, if the hull breaks and the noodles just come out. I just don't want to pop my boat seams with expanding spray foam... I gotta do some test sprays and get some experience before I decide. I appreciate all the views, food for thought!

Get the 2lb two part foam. Forget the spray if you don't want to chance it. I wouldn't. It's not worth it to me.