Help! I just cut a 5" hole in the rear of a P18 hull so I can do an internal transom repair. When I finally trimmed it so the "curved" inspection port would go in, I discovered that the curve of the port is no where close to the curve of the deck! There's about !/2" gap on either side. Did I buy the wrong port? Does Viking make one that's really curved, or do I have to make a couple of giant fillets? I'm in for good now, and I like the idea of a port there, because I discovered all kinds of crap inside.

Thanks in advance for any and all help

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Repairable P18
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You are looking at a couple of BIG fillets. The curved ports are no where near enough curve for a p18 behind the rear crossbar. I put in a 4"x6" port on my p18 and had to do extensive glass work to integrate it. I will try to post some pictures and a detailed description of what I did late tonight.

The curved ports are intended for something closer to the slight curve of the deck like you might find midships somewhere. if you can't get it to work you can always glass the hole back in when your repair is done.

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Dustin Finlinson • Magna, UT
Member: Utah Sailing Association
1982 Prindle 18
1986 Hobie 17
1982 Prindle 16
1980 Prindle 16(mostly)
1976 Prindle 16(mostly)
Check out "Prindle Sailors" on Facebook.
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Thanks for the posts guys! Thats really the info I needed; I just wanted to make sure I bought the right port, and not the "half curve" one when I should have got the "full" or whatever. Rider I'm ok without pics, but thanks for your help! Quareth I decided I should stay my course for the duration here simply because I've pulled out at least 5 pounds of sand and eco-system from the stuff that got trapped behind the rear beam support....I can't wait to see what I find in the other hull.

Soooo I'm thinking of using balsa wood from a hobby store to bridge the gap. But I got to thinking....does balsa wood rot? I do intend to cover it fully with epoxy/glass, but I know saltwater is like a bad rash and gets wherever you don't want it. Maybe a cedar chunk would be better. Thoughts?

And thanks again

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Repairable P18
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use epoxy with a lot of microballons. tape off the area around the port so that you can remove the excess and smooth and shape the epoxy so that you will have minimal sanding.
marc



Edited by marcs2 on Mar 14, 2012 - 05:46 AM.

Check the West manual Figure 19 p9 "creating a base" I'm no expert but the thickened stuff is pretty easy to work with. Go with some 406 for strength and 410 or 409 to fair.

Keep in mind that if the gap is more than 1/2 don't fill it in 2 coats to prevent a melt down. - Don't ask how I know that

Also you will need to paint / gel over the epoxy or it will yellow and deteriorate.

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Bob Miller
1983 P16 Sail # 7312
"Miller Time" A work in progress; out of the water for 16 years
Barnegat Bay NJ
Beach Cat Lesson #1 - A free cat isn't
Find more Prindles on Facebook https://www.facebook.com/groups/173120656090532/
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Thanks again for the help

OK so I'm looking at another trip to West Marine. Bobcat you mean I SHOULD lay it all up at one time...NOT two/three coats? I guess I gotta get the fiberglass book from WM too. Goodbye money

Before its all over with I'm going to spend twice the puchase price of this boat just to get it back to the shape it was in when I bought it. Sigh

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Repairable P18
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DO NOT LAY IT IN THICK

It will melt your boat or the port or both


look online for the manual, i think its free if not Ill help you out

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Bob Miller
1983 P16 Sail # 7312
"Miller Time" A work in progress; out of the water for 16 years
Barnegat Bay NJ
Beach Cat Lesson #1 - A free cat isn't
Find more Prindles on Facebook https://www.facebook.com/groups/173120656090532/
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Bobcat found the manual online pretty easy. I'll try to read most of it this weekend. All I have for the filler stuff is 406 so I still need something thicker I guess, but I'll read up first. If you're ever in Texas I'll buy you a beer or six

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Repairable P18
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Read into what you need a little more but it looks like you are good to go using 406. Depending on your skill with epoxy and a sander you may want to pick up one of the fairing compounds to make the final fillet look nicer since the fairing compounds sand easy.

Or just run the 406 use the application stick to make the fillet around the port and see what you get. Either way shouldn't break the bank if you've got the 105/205 already I think the fairing compound is only $12

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Bob Miller
1983 P16 Sail # 7312
"Miller Time" A work in progress; out of the water for 16 years
Barnegat Bay NJ
Beach Cat Lesson #1 - A free cat isn't
Find more Prindles on Facebook https://www.facebook.com/groups/173120656090532/
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Consider using polyester resin available at auto parts stores and Wal-mart. It is generally cheaper and you can gelcoat it in the future if you want to. I use epoxy for internal repairs and polyester for external repairs.
If you are worried about creating a weak spot around the port add a few layers of epoxy fiberglass on the inside of the hulls around the edge of the port.
Also be sure to dig out a little bit of the foam core and refill the space between the voids with thickened epoxy or polyester resin.
I just used baby powder for a thickener and it works great. Handy cheap, and effective.

So for some reason last night I could not sleep and this problem popped into my head and I had some ideas about it. it may be hard to explain without a diagram or something but I'll try.

First I would trade out your curved ports for flat ones. Find something like a 5" PVC pipe that you can slide into your cut hole. Make it long enough that when the bottom of it touches the inside of the hull the top can be even with the highest point of the hole you have cut out. You would make cap or wooden plug to fill in the top of the pipe so you have a flat surface. you would have to remove gelcoat down to the glass all around the hole and rough sand it good. Wrap some plastic wrap or something around the pipe so the pipe can be removed from the new fiberglass your going to put on it. I am not a glass expert but if you might can use something like a form release agent on the plastic. Anyway layup fiberglass around the pipe joining it to the hull. Lay it flat over the top and sides build it up kind of like the ports up front look like. it will be a bit more extreme than that but same idea. The goal is that you can then cut a slightly smaller hole and put in the smallest port you can. When you cut you should hopefully have at least a good half inch of flat glass on top on the outside of your new hole to attach a flat port to.

I have also put some thought into getting the pip out. If you cut it in two pieces but reconnect them using something that can break away like masking tape you can pull them out the front port when you are done. Just drill small holes and attach a line that runs out the front port before you start. make it strong enough you yank the bottom half out from under it so the top has no support. Then you can pull the top half. If you think the top might get too stuck you could sink a big bolt or screw into the wood plug in the middle and glass around that since it will be cut out anyway and you can tap on it with a hammer to knock the pipe out of the form.

You will need to spend a fair bit of time filling. fairing sanding and gel coating but potentially could be as solid as the original.

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Dustin Finlinson • Magna, UT
Member: Utah Sailing Association
1982 Prindle 18
1986 Hobie 17
1982 Prindle 16
1980 Prindle 16(mostly)
1976 Prindle 16(mostly)
Check out "Prindle Sailors" on Facebook.
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Actually, I did something really similar to this when adding speakers to my 5.2.

I agree, you'll want a flat port, (or marine speaker =), not the curved one. I'm going to tweak the rest though..

Take a 1 or 2 gallon plastic flower pot, and cut the bottom off. Cut one side all the way down, too, so you can roll it like a scroll.

Put the rolled up flower pot into the hole you've cut* for the inspection port, and let it expand.

Make up some thick fairing compound and slather it all over the edge of the hole. It's easy enough to sand down that too much isn't an issue, as long as you don't make it so thick that it heats up. It took me about 3 layers of fairing compound when it was said an done...I'd just do two at first though. After you've got two layers on, and a decent purple build up, and it's all dried and cured (24hours-ish for the 2nd layer) pop the flower pot away from it and pull it out.

Grab a durablock and 60 grit and start shaping. It'll take less than 15 minutes. You'll quickly see if you need to add some fairing compound to get a flat smooth surface.

After it's fair, clean it up and add gel coat preval sprayer...or your choice of topcoat. I'm terrible with gelcoat so I can't help you much there.

Mark your holes, drill, and pop rivets.


*If your hole is too large for the port I'd think about getting a larger port. Otherwise you're adding a layer of glass and there's almost no reason not to just fill the hole/whole thing. If the hole is too small, you can lay the port on a piece of wood, cut out the center, then use the wood for a jig on the hull (as you can use the 6 holes in the port to fasten the wood to the hull)

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Rob
OKC
Pile of Nacra parts..
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