Did I screw up? Trihull transom and stringer replacement

electric603

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I hope I did not mess up by taking off the cap and the deck. In the pictures you can see that the cap is not completly off the boat. I just slid it forward to get at the transom. Should I put the cap back on and take some mesurements or can I just measure the inside of the cap and pull the sides in to those measurements when I tab in the deck? As for the bottom should I put some temporary bunks undereath and lift the keel off the rollers or what should I do to keep the shape of the hull? Thank you for any advice. If my pictures are too large please let me know. I am still learning how to post them.
IMAG0396-1.jpg
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jbcurt00

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Re: Did I screw up? Trihull transom and stringer replacement

Big pix are good.

You could measure the cap & pull the hull in to match, I wouldn't, besides it would be much easier & much more accurate w/ the cap correctly located over the hull & then pull the measurements.

If you are expecting to pull the deck & probably the stringers you'll want to build a cradle to full support the hull while you work on it.

Since the boat will never be lighter then w/out the deck & cap, if you need to or want to, do any repairs on the exterior hull, and the keel, it will be much easier to flip it & work on the hull facing up. The cradle could be made dual purpose to hold the hull upright then when the time comes, it can be re-tasked to hold the boat upside down.

Look for WoodOnGlass's Blue Flamingo thread, he's got good stuff there & a nice cradle. Read thru the threads in Don's Helpful info thread.. Friscoboater & oops both have really good resource threads in Don's list.

Welcome the iBoats dry dock
 

electric603

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Re: Did I screw up? Trihull transom and stringer replacement

Thank you for the reply. If I put the cap back on do you think the weight of the cap will force the hull bottom out of shape with the deck removed and the soggy stringers? Where should I take the measurements from?
 

jbcurt00

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Re: Did I screw up? Trihull transom and stringer replacement

You can look down the bottom of the hull, in both the 'flat' areas between the chines & along the chines to see if there has been deflection. Esp if the transom is soft & has had a motor hanging off it for years, w/out having the transom for support & bunks under the transom to support all of the above, can cause a 'hook' to develop in the hull. Here's an iBoats thread about a hook in the bottom of an aluminum boat, that should help explain what I meant.

A neglected boat, w/ soft wood, filled w/ water for long periods of time, and not well supported,- would be more of a long term problem then anything you'd do now. But moving around in the boat (your weight & moving around), adding back materials (more weight)and glassing them in to place could all contribute to minor distortion becoming permanent.

My FireFlite will distort out about 4"+ on either side of the hull when I lift the cap off. At 15' long, I am spacing my cross braces at about 5' centers. The blue in this drawing are the crossbraces @5' apart, that gives me some room to work on the deck between the braces. If it looks like I need more support, I'll add the red diagonal gussets.
Crossbracing.jpg


This will keep most of the space between the braces open & add support. my FireFlite has a little bit of contour as the gunwales move from the stern/transom forward. So I too measurements about every 18". It looks like that will give me enough reference when I start the put back. You may need more measurements, or fewer depending on the actual shape of the hull. I pulled the dimensions from the inside face of the hull bottom lip at the cap/hull joint. Depending on how your cap fits onto & is attached to the hull, you may or may not be able to measure from that lip as well.

This is my cap/hull joint:
RubrailHullCapjoint.jpg
 

electric603

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Re: Did I screw up? Trihull transom and stringer replacement

I will put the cap back on to get the mesurements. There is a hook on the bottom due to the short bunks on the trailer. Do you think this will straighten out with the new stringers or will I have to fill and fair the bottom back into shape.
 

jbcurt00

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Re: Did I screw up? Trihull transom and stringer replacement

There is a hook on the bottom due to the short bunks on the trailer. Do you think this will straighten out with the new stringers or will I have to fill and fair the bottom back into shape.

Depends on how bad a hook it is. Somewhere I read about someone trying to force the hull back into shape w/ the stringer at it's installation. That's not a great idea, for many reasons, tension & stress cracking among them. If it's a permanent defect, fill & fair is about the only option I'm aware off. If you move the bunk/hull so that it bears the boats weight better, it might relax some, but probably not.

You can try googling boat hull hook repair or on YouTube, there may be other options available.
 

electric603

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Re: Did I screw up? Trihull transom and stringer replacement

Thank you for all the valuable information.
 

jbcurt00

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Re: Did I screw up? Trihull transom and stringer replacement

You are most welcome.

Read thru some of those threads in Don's list, tons more info there and look up WoodOnGlass, his signature links & threads are invaluable resources as well. Not to mention he's around fairly often to lend a 'hand' or suggestion when you're stumped in the middle of a step/stage of the demo &/or put back.

I'd suggest you also might change the title of your thread to something like:

1972 Starcraft Trihull stringer, deck & transom repair


Or something similar & relevant.

Other folks that have similar boats may swing thru & take a look or help out. And it will be easier for someone who comes after you to find your thread & use it as a resource for their own resto.


At the bottom of all threads, the iBoats server also lists similar threads that might be helpful to read thru as well, while your reading thru some of the other threads in the resto forums.
 

Scott Danforth

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Re: Did I screw up? Trihull transom and stringer replacement

i would take the cap completely off and then work on the hull. that would be the only way that I know of to get the hook out.
 

jbcurt00

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Re: Did I screw up? Trihull transom and stringer replacement

i would take the cap completely off and then work on the hull. that would be the only way that I know of to get the hook out.

I thought that's what electric had planned to do after taking some dimensions w/ it slid back in place.

If not, I agree completely, cap off.

The getting loose part has already been done. And the more weight you can get out of it before you support w/ cradle & start replacing stuff, the more likely the hook might relax, if only a little
 

electric603

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May 4, 2012
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Re: Did I screw up? Trihull transom and stringer replacement

I'd suggest you also might change the title of your thread to something like:

1972 Starcraft Trihull stringer, deck & transom repair


Or something similar & relevant.

I already have a thread started for the rebuild. Is there a way I can move this into that thread?
Thanks again for the info.
 

jbcurt00

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Re: Did I screw up? Trihull transom and stringer replacement

You can PM a moderator (it will be under their name, where your avatar reads cadet) and ask them to move it for you.

You can also use the reply w/ multiple quote button, it's the 1 farthest to the right at the bottom corner w/ the:

Reply _ "Reply with Quote _ "+

Just click that multiple quote button under all but the last of the 12+/- posts to your thread, then click the Reply with Quote button & a reply window will open with all the posts quoted, just like you quoted mine above.

Cut & paste that into your resto thread...

If you go to your profile page, you can edit your signature to include a link to your resto in your signature line, like many of us do.
 

electric603

Petty Officer 2nd Class
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May 4, 2012
Messages
168
Re: Did I screw up? Trihull transom and stringer replacement

Thanks JBC, I have moved this to my resto thread and put the link in my signature line.
 
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