1969 SF20 Restoration "Sandy Paws"

[TMala]

A little video showing the cavitation during running. The boat is getting an annoying porpoise which it did not have before. I raised the engine to the 4th hole. It appears it is still buried from the video, I might buy a jack plate. I have another post about this in the performance section, sorry if i'm being repetitive!

https://www.youtube.com/watch?v=BJN1...ature=youtu.be

We put on our wetsuits yesterday and took advantage when the wind dropped out to try and get some clams here in NJ. It was a bit foggy rainy and cold but we managed our limits! Clam chowder and clams casino with some wine followed after, good day on the water! Boat ran a bit better with the weight of the clam basket forward haha. It was good to get the decks dirty. I applied the alexseal polymer sealant wax a week ago and it makes it easy to keep clean.

[steel686]

Maybe some of the “elders” will speak to this but is there a chance you have any hook from where you wrapped glass onto the bottom. Isn’t that the biggest issue with doing a transom from the outside. Is that contributing to the porpoising?

[TMala]

I thought about that a lot and would love to hear what everything thinks about that.

I did a little reading and it seems if I had a true hook I think it would eliminate porpoise and cause the bow to go down like a trim tab. Some builders actually add a hook to their hulls to help the boat ride straighter.

I was going to take the boat out again this week to raise the engine another hole. I will double check the aft to see if i'm deficient in some areas. It seemed pretty straight as I was grinding at it, but worth another check!

[steel686]

Great to see you putting some love into that boat. I know it well from the Cape. Send me a PM some time. I'll try to dig up a picture of a friend taking his 20 to the altar. Good move.

[jtharmo]

Originally Posted by TMala

I did a little reading and it seems if I had a true hook I think it would eliminate porpoise and cause the bow to go down like a trim tab. Some builders actually add a hook to their hulls to help the boat ride straighter.

I was thinking rocker more than hook, especially on the center panels. In your video, I was trying to notice if water was coming off the transom funny. It is hard to tell. How is the planning speed before and after? A higher planning speed may be a symptom of a loss in lift that contributes to porpoising if combined with a change in cg. Have you gone through Bushwacker's and Capt Terry's stickies at the top of this page?

[TMala]

Good point, I will try and check my min plane speed next time out. I am getting about 5900 RPM and a little over 40mph out of the Suzuki 140 with the stainless three bladed prop. My cavitation plate is still too low as I am having a hard time seeing it.

Yes its great info on the stickys. I may have done more to my center of gravity than I thought going from a 387lb engine to a 420 lb engine. I tried to compensate for this by moving two batteries from stern to console, and pushing gas tank COG foward by about 3 inches. If I had to do it again I may have pushed gas tank forward a bit more OR gone to a bigger tank which I still may do. I also took weight out of the bow by cutting out part of the forward casting deck, hmmm.

From going through those sticky's, it seemed that jack plates, doel fins, and 4 bladed props were all used to try and get planing speed down.

Gonna take the boat out tomorrow and raise the engine to the lat 5th hole, inspect any rocker on the stern. Maybe also contemplate a Permatrim, I have read a lot of good about them and can't see it doing any harm.

[TMala]

Just following up after a few months of use after the restoration.

This boat is AMAZING! I have gotten a lot of hours on her, sometimes every day when I was laid off from work and the fishing was good here in NJ. MPG is great with this engine, plenty of power. The boat did well out front and through the inlet on many striped bass trips this spring. I got my biggest striper to date, picture below, the fish measured 49.5 inches and released, maybe 50lbs, I will never know. I also got my biggest to date on one of my custom plugs at 43inches also pictured. We got plenty of keeper fluke to make fish tacos and Civiche with this spring as well, the boat raises fish!

I added the Frigid Rigid. Check these coolers out, google them, they are the best! I was lucky to find this one used. Picture below

I had the boat out of the water this week for a mid season clean up, oil change, powerwash and apply some of the AlexSeal polymer. I also repainted the bottom as build up was accumulating even though I painted it this spring.

Permatrim is doing great. Last week back from the sandbar heading in to a 20knt south wind we could get down to about 12knts planing speed when the chop kicked up to uncomfortable, i'm happy with that.

Here are some pictures taken last week at the sandbar and one from the spring with the bass. I can't say enough for this do it all boat, great ride, sits in the slip 24/7 no problems easy to use. The AlexSeal is holding up great, transom is doing well. I hope everyone is enjoying their 2020 season! Seeya on the water!



- Tom

[JohnC]

I can't see the cavitation plate in your video. I looked at YouTube and found this one https://www.youtube.com/watch?v=oNFVMjJ_vUA
The plate is visible in this video but still fully submerged. It would be best if someone more knowledgeable confirmed but it looks like the motor is too low to me.

[TMala]

Thanks John, Sorry i haven't been monitoring the thread! I raised the engine another hole after the video was taken and added a permatrim which has helped out. No porpoise now unless the engine is tilted up too high on cruise. The permatrim I mounted is black so it's even easier to see it now in the water on cruise. The permatrim is nice, aluminum and not plastic and the slow plane speed is better now as well. Sofar so good on this rig, still fishing good days and bad, gets lots of compliments. I have owned and partially restored 5 other boats before this one older and newer, this one gets the most compliments, seems a lot are familiar with the seacraft way of life! Hopefully everyone is having a great season!

[uncleboo]

Nice work...the boat and the fishing!