Another 25 Seafari goes under the knife - Page 37

Islandtrader · #**361** 04-28-2012, 08:55 AM

Quote:

Originally Posted by Blue_Heron

The windshield frame was soaked with epoxy resin thinned with xylene (home made penetrating epoxy). Both were sprayed with Interlux Perfection Plus varnish. So the hope is that the epoxy protects the wood and the varnish protects the epoxy.

Dave...After the fact information. In a general conversation with a couple of friends that have boats both mentioned that when they put epoxy down and then varnish over the top, the epoxy started to cloud after a few years and that the varnish did not filter out enough uv. One was over teak and the other over mahogany.

Now maybe since you thinned yours down and your boat is a trailer queen and not sitting out 24/7 you will be safe...however if it starts to cloud you will at least know why.

Blue_Heron · #**362** 04-28-2012, 01:58 PM

Quote:

Originally Posted by Islandtrader

... the epoxy started to cloud after a few years and that the varnish did not filter out enough uv.

Yes. That's the risk with epoxy, and it's why I'm considering this an experiment. I used Raka's low blush epoxy because it performed well in the epoxy test I found here:

http://www.oneoceankayaks.com/Epoxyhtm/epox12m.htm

I plan to keep the boat covered, so hopefully it won't cloud for a long while.

Dave

Blue_Heron · #**363** 05-04-2012, 09:48 PM

Quote:

Originally Posted by seafari25

I think Dave will be modifying his tabs, similar to my Grandfathers so maybe he wont notice any issues.

Going back a ways here, but I need to give credit where it's due.

In email conversations with strick and Bigfluke over the past two years, it's apparent that the 25 Seafari needs plenty of trim tab authority to function well. For most boats, the closer you can mount the tabs to the chine, the longer your moment arm, and the more effective your tabs will be. But the outer step on the 25 Seafari is only about 9" wide, so if you go as far outboard as possible, only the outer 9" of your trim tabs comes in contact with the water as you start to lower them. As an illustration, here's the port trim tab on my 20sf:

The trim tab isn't much wider than the hull panel, so most of it is in contact with the water as you begin to trim it down. Contrast that with the trim tab on the 25:

On the 25, a significant fraction of the width isn't in contact with the water until you trim it down about 50%. This video is very short, so you may have to play it a couple times, but you can see how the water on the inboard side of the tab is out of the water:

So what is the solution? Well, Brandon's Gramps came up with a good idea. He scabbed a metal plate to his tabs that would follow the step in the VDR hull:

I thought about doing the same thing with some SS sheet metal I had, but I didn't think my material was thick enough. And trying to bend SS sheet to match the hull would have been no fun at all. So I decided to use my recently acquired fiberglass fabrication skills to make some trim tab extensions. I'm happy with the results:

You can see in the picture that I added a SS angle at the outboard edge to catch spray and channel it back along the outer edge of the tab. I'm not sure if it makes the tab extension more effective, but it does stiffen the edge of the fiberglass panel. This video shows the tab extensions at work:

There is a noticeable difference in performance. Trim tab response is much more pronounced. I was playing around with trim on the river last Sunday. With the tab extensions, I got the boat to stay on plane at at 13 mph with less bow rise than I was getting before at 14 mph. It's actually pretty sweet.

More to come... I'm doing the prep and finish work on my swim platform and engine cover. I hope to get those both done in the next week or so. I also need to get my VHF and stereo installed. The VHF for obvious offshore safety reasons, but it's a tradition to listen to classic Buffett when we're trolling for Dolphin, so I've got to get the stereo done in the next couple weeks.

Dave

strick · #**364** 05-05-2012, 02:06 AM

Dave

Looks like they are working great! Do you mind if I copy that

How do they behave in a hard turn?

strick

Blue_Heron · #**365** 05-05-2012, 07:51 AM

Quote:

Originally Posted by strick

Do you mind if I copy that

I'd be honored, Dr. Strickland.

I didn't notice any difference in the turns. I'm still getting used to the boat, though. I've only got 4 hours on the clock.

Dave

strick · #**366** 05-05-2012, 11:02 AM

Cool thanks. I've been working on the interior of my 25. Have the head liner in place and finishing the wood work. I need to put some spreader lights in. May take it for a ride this weekend if I can get away from work.

strick

Blue_Heron · #**367** 05-05-2012, 04:03 PM

I added a little extra laminate on the underside of the swim platform at the bracket and swim ladder locations earlier this week.

Today, I got the swim platform and the engine box primed with 545 and patched the small nits.

Tomorrow, I'll block sand them and shoot them with the final coat of 545.

I also shot the swim platform brackets with gelcoat/dura tech clear gloss.

Next thing is to drill some holes and they're ready to bolt to the transom.

Dave

cdavisdb · #**368** 05-05-2012, 04:31 PM

Dave, I love the tabs! Gotta do something like that to mine.

I'd like to know how it handles in a very hard turn. Mine lays over on the V, the keel loses hold on the water and the boat starts to spin. Gets your instant attention(not in a good way), but she stays totally stable while spinning. I wonder how that outboard lip will affect the spin.

Strick,

Post some pics of what you are doing with the headliner. I'm still at a loss about what to do with my mouse fur.

Connor

seafari25 · #**369** 05-05-2012, 06:10 PM

Hey Dave,

Not only would Gramps be proud, he would also be very impressed, as I am!

It's nice to know, that I, thanks to my Gramps, have finally contributed some useable info to this site, instead of taking it all the time.

It didn't occur to me to make them out of fiberglass but I'm sure they're just as strong, and will probably outlast ours...we have 30 years so far:P Seriously though, great thinking and excellent work! It's tough to tell in the pics but is the forward edge of the lower panel, curved upward like ours? I think that's important to ensure no water forcing downward on the plate.

Also, it's great to hear your comparison, with and without. I have never operated ours without, but I can see by your experience, my minimum planing speed would be much higher, and sensitivity lower as I had anticipated. I'm glad Gramps was on top of that!

12 mph is pretty darn good!

Nice work!
Brandon

gofastsandman · #**370** 05-05-2012, 07:22 PM

Quote:

Originally Posted by seafari25

Hey Dave,

Not only would Gramps be proud, he would also be very impressed, as I am!

It's nice to know, that I, thanks to my Gramps, have finally contributed some useable info to this site, instead of taking it all the time.

It didn't occur to me to make them out of fiberglass but I'm sure they're just as strong, and will probably outlast ours...we have 30 years so far:P Seriously though, great thinking and excellent work! It's tough to tell in the pics but is the forward edge of the lower panel, curved upward like ours? I think that's important to ensure no water forcing downward on the plate.

Also, it's great to hear your comparison, with and without. I have never operated ours without, but I can see by your experience, my minimum planing speed would be much higher, and sensitivity lower as I had anticipated. I'm glad Gramps was on top of that!

12 mph is pretty darn good!

Nice work!
Brandon

12 is outstanding! Close to Wahoo trim.

Cheers,
Looks nice for us chickens in the am. Come on with the big moon.