Stumble pads

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So will these help a tunnel hull handle better and replace using a turn fin? I noticed the PB Stiletto EP has them and no turn fin but I need to get a nitro boat running.

I have a few older turn-fin style hulls that I am in the restoration phase so now would be the time.

One is a Prather lapcat 3 stripped to glass, a Dumas hot shot sprint 21 ABS, and another is a fiberglass no-name large tunnel hull that I got for a K&B 13cc.

So they look like balsa and I guess epoxy them on before applying primer and paint? If I saw them myself I guess each hull will have it's own size?

If I could afford better hulls to start with I would and just put these back on flea-bay but I spent all my money on motors so I have 2 or 3 of each size of K&B outboard. I would love to get into newer style hulls but even a gallon of xylene and a quart of fiberglass primer has me stalled out right now.

I got a few colors of paint and a quart of 2 part clear polyurethane.
 
Any tunnel made in the last 15 years hasnt had a turn fin. There is no need for a turn fin in a properly designed and built tunnel. Most use stumble blocks to help keep the front from hooking when the boat sets for the turn. They wont help the boat turn any better.
 
Hey Harry,

They won't necessarily help a tunnel hull to handle better, it depends on the hull type and the setup. Some hulls are designed with them from the beginning and work very well, some hulls don't need them, and some benefit from adding them to help handling.

Stumble blocks/pads certainly won't replace a turn fin. The older style hulls that you have probably won't work so well without turn fins, it depends on the sponson deadrise, ride surface width, amongst many other things. The stumble pads generally prevent the nose of the boat from dropping too low in the turns and hooking. The lower deadrise hulls that you have are a lot more likely to slide and do a wide turn rather than hook and pull in tight.

I would say don't epoxy them on in the first place. Get your hulls running with / without turn fins to see how they handle. The stumble pads can be added on with double sided tape to see how they work. If they don't work, then they are easy to remove. If they do work, they can either stay on as-is, or you can attach them more permanently.

The main thing is, enjoy getting a nitro tunnel running and then start tinkering with adjustments to see what improvements can be made. Have fun!
 
Thanks for the great knowledge, feedback and encouragement.

Hopefully this summer I will get all 3 in the water. The EP is ready to go now when I get a battery.

In a few weeks I will have a skiff running and can take them to a lake and be able to retrieve them safely without driving all the way to Orlando and meeting up with the club guys, about an hour drive one way. I have small ponds all around here but next to houses and I think the noise will be a problem. It has been depressing not having a place to go. When we were kids we would take a lot more chances.
 

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