Wet or Dry Sponson 1/8 Scale or Thunderboat

[Bob Morton]

Hi,

So what do you think is best, Wet meaning opened at the sponson transom. Dry meaning no holes at the sponson transom.

Bob

 

[Scott Schneider]

Hi,
So what do you think is best, Wet meaning opened at the sponson transom. Dry meaning no holes at the sponson transom.

Bob

Dry .... why would you want an Auto Sinking Hull ?

 

[Greg Hahn]

Hi,
So what do you think is best, Wet meaning opened at the sponson transom. Dry meaning no holes at the sponson transom.

Bob

Bob, you may already know all this but this is my observation. Most of the older full scale boats I've seen had what you call "wet" sponsons. The exact reason for this I'm not sure but from a design/engineering standpoint some of that had to do with releaving air compressioin. Meaning that as the boat rides rough water and the hull flexes it allows air to flow in and out of the hull easily.

Because I had trouble with this very thing on my 68 Bardahl I now leave holes in the rear transome for the non-trip cavities and also holes in the sponson transomes for the the front cavities.

The first time my Bardahl blew over (you were there) it landed inverted very hard and the impact compressed the decking enough that the trapped air blew out the deck seam. To eliminate that problem I now leave holes and simply tape them over when I run, the compression will blow out the tape instead of a glue seam.

This worked perfect when when my Bud boat blew over last year. The tape blew out instead of the deck.

gh

 

[Grimracer]

I vote for DRY with the tape method..

Hydroing the deck off as Greg did is a bummer but so is picking a 35lb full wet boat into the chase boat when its full of water.

Running the boat like the real wet boat just does not work all that well for us.

Grim

 

[Bob Morton]

Hi,
So what do you think is best, Wet meaning opened at the sponson transom. Dry meaning no holes at the sponson transom.

Bob

Bob, you may already know all this but this is my observation. Most of the older full scale boats I've seen had what you call "wet" sponsons. The exact reason for this I'm not sure but from a design/engineering standpoint some of that had to do with releaving air compressioin. Meaning that as the boat rides rough water and the hull flexes it allows air to flow in and out of the hull easily.

Because I had trouble with this very thing on my 68 Bardahl I now leave holes in the rear transome for the non-trip cavities and also holes in the sponson transomes for the the front cavities.

The first time my Bardahl blew over (you were there) it landed inverted very hard and the impact compressed the decking enough that the trapped air blew out the deck seam. To eliminate that problem I now leave holes and simply tape them over when I run, the compression will blow out the tape instead of a glue seam.

This worked perfect when when my Bud boat blew over last year. The tape blew out instead of the deck.

gh

Thanx for your reply Great answer. always learning

 

[Bob Morton]

I vote for DRY with the tape method..
Hydroing the deck off as Greg did is a bummer but so is picking a 35lb full wet boat into the chase boat when its full of water.

Running the boat like the real wet boat just does not work all that well for us.

Grim

Nike, thanx for your reply. I use the tape method also. Great reply

 

[Hydro Junkie]

If I remember correctly, I was told by Ted Jones years ago that the reason for the open sponsons was "stability at the dock". He felt that the boat would be more stable with flooded sponsons. This was found later to be untrue and, since the late 60's or early 70's, all boats have been built with sealed sponsons. In the case of R/C hydros, a 1/2" or so "drain" hole in the back of each sponson would probably be ideal for the reasons listed in earlier posts

 

[jayt]

Joe Taggart's son told me it had to do with eliminating mold and rot - "sealed" sponsons would always trap some water and end up rotten and weak over time. Better paints and sealers with mold retarders finally eliminated the problem.

.

 

[Bob Morton]

Hydro Junkie, Jyat Thanx for your replys

 

[Hydro Junkie]

Rotting could very well be involved as well, since both the Slo-Mo's were taken down to Arizona every winter to "dry out" after the racing season ended.