'74 Holiday 18 Restore Mod.... Convert to open bow.

[Paulwise]

Welcome Paul (from YouTube)!!

great job on that 2-part foam removal. that stuff is a nightmare as I'm sure you're aware.

You're knee-deep in a "bowectomy". These are ambitious builds but it looks like you're off to a good start...nice clean cutout that meshes with the existing gunnel beautifully.

The dash is a significant structural piece...i assume you're adding a raised bow deck with consoles.

my obligatory PSA : I've already provided my advice on glassing epoxy. Fir wood grains are going to check and allow water intrusion...epoxy will hold it and promote rot. Epoxy on it's own is like a brittle candy coating.

I wonder if those fittings (doubt they're Cu...maybe brass or bronze) are for running kicker fuel line and maybe control(s). would a 5/16" fuel line fit through there? where there also holes in the transom wood there?

Hi, Please see my conversation with Boys n Toys about hull rivet repairs. I think you did this in your rebuild. Do my thoughts about this repair sound correct?

 

[classiccat]

Heres what i found, the last set of rivets on the end of several ribs on the port side are stressed and have slightly lifted, much less on starboard side. I cant get my fingernail under any of them but this will explain why only the port side has black tar looking sealant on the inside of the hull. I only found 1 set of rivets that i think has hairline cracks on either side of the rivet heads. I imagine that repairing these will be a matter of drilling out any that look lifted at all and putting a small plate there and riveting them back down firm with a sealant on each replaced rivet and on the back of the plate. Maybe 2 sets in on each rib that needs it, so 4 replaced rivets total on each rib? Does this sound appropriate?

I like 8 - 10 rivets per rib-end for that patch buttered with 3M 5200.

• 4 for the existing rivets
• 4 outside of the crack stop holes
• debatable: 2 for the crack stop holes themselves...I did this but it could be argued that if the boat flexes again, there's another stress riser right there. I took measures to make sure my 18SS won't flex again

1:35 in:

 

[classiccat]

Yes at least one has a hole going through the riser then into the hull area. Heres a question, can i hook a separate gas line to my kicker through a Y split from one gas tank? Or should i just resign to have 2 tanks? Ill check the gas lines i have for a trial fit. I was happy with the bow cut out as well. Thinking about the design the structure for the bow deck is mind numbing haha! I can install float foam in the mean time.

Yeah that shouldn't be a problem tapping into the main fuel feed. I don't believe that it will effect operation. The only reasons I can see keeping them isolated is if it's a 4 stroke and your main engine is a 2 stroke (or vice versa) or you like to push the limits on your fuel capacity and your kicker with a separate small tank is your ticket back to port should you push a little too far.

 

[Paulwise]

It could be argued that if the boat flexes again, there's another stress riser right there. I took measures to make sure my 18SS won't flex again.

Was that the plates you put on the inside of the hull?

 

[classiccat]

Was that the plates you put on the inside of the hull?

correct. spray rail reinforcements as well as the vertical risers.

 

[Paulwise]

correct. spray rail reinforcements as well as the vertical risers.

Really appriciate the info. Would you recommend any particular rivets for this repair. I know that they should be bra head but brand and length is the question i guess. Also what size were the repair plates. Thanks for any info.

 

[classiccat]

Really appriciate the info. Would you recommend any particular rivets for this repair. I know that they should be bra head but brand and length is the question i guess. Also what size were the repair plates. Thanks for any info.

Here's @Watermann s thread: everything rivets.

We like the brazier head 3/16" structural solids for this repair.

 

[Paulwise]

Here's @Watermann s thread: everything rivets.

We like the brazier head 3/16" structural solids for this repair.

Wow My learning curve here is my biggest hangup. Im a rivet rookie.....He recommends having 3/8 and 7/16 lengths on had. I did find 3/8" so im good there. having trouble finding a 7/16" length. Would a 1/2" work? .... everything is the correct T4 alloy so that is a small win! Also my brother is letting me borrow his solid rivet air gun kit from ingersoll rand so thats amazing as well! He has been down the boat repair road before thank God.

 

[renns]

I ordered rivets from Aircraft Spruce. They sell by weight, going down to 1/8 lb for small orders. https://www.aircraftspruce.com/catalog/hapages/solidalumrivets2.php

They have a place in Canada as well, if you happen to be north of the border.

 

[BOYS & TOYS]

I see Classiccat has got it covered. I was lucky to not have that problem and I added a reinforcement to ovoid it.
1/8" 5052 aluminum bent to fit the top of the ribs and to the hull sides. All the solid rivets are above the water line and blinds in the rib tops. Bonus of covering the multiple holes from old deck rivets

 

[classiccat]

Wow My learning curve here is my biggest hangup. Im a rivet rookie.....He recommends having 3/8 and 7/16 lengths on had. I did find 3/8" so im good there. having trouble finding a 7/16" length. Would a 1/2" work? .... everything is the correct T4 alloy so that is a small win! Also my brother is letting me borrow his solid rivet air gun kit from ingersoll rand so thats amazing as well! He has been down the boat repair road before thank God.

that's nice having an experienced rivet partner! 1/2" length is fine; you're better off with longer rivets and trim them to size if you find the bucktails rolling over on you.

 

[Watermann]

Looks like someone before did a real sloppy Coat it job on the inside.

I see you have a 74 which is pre-factory rib end/spray rail braces. Running a boat of that era 18' and up mostly with rot compromised transom, decking and side panels normally accounts for rib end cracks as well as possibility of the dreaded pray rail chine split.

Adding the patch to the outside at the rib ends like you said is an accepted method of repair but may not be a cure for future issues.

 

[Paulwise]

Looks like someone before did a real sloppy Coat it job on the inside.

I see you have a 74 which is pre-factory rib end/spray rail braces. Running a boat of that era 18' and up mostly with rot compromised transom, decking and side panels normally accounts for rib end cracks as well as possibility of the dreaded pray rail chine split.

Adding the patch to the outside at the rib ends like you said is an accepted method of repair but may not be a cure for future issues.

What else can be done to prevent it? I have seen spray rail braces added as well as additional risers and floor supports to shore up hull integrity. If you were me would you do these things? As of right now I am putting patches on 8 ribs that were slightly lifted. I believe the damage you have described was in its beginning stages with this hull. I did have a very rotten boat but the PO didnt use it much.

 

[Paulwise]

Looks like someone before did a real sloppy Coat it job on the inside.

yes, PO did a very half ass refurb on her a while back.

 

[Paulwise]

Pics of splash well tare down

 

[Paulwise]

The steel Mounting of this bracket was causing problems. Can I opt to NOT put it through the transom with bolts but screw it into the transom with SS lags or something?

 

[Paulwise]

JB Marine for filling unused holes.

 

[Paulwise]

Beginning of rib end repairs.

 

[dingbat]

What else can be done to prevent it? I have seen spray rail braces added as well as additional risers and floor supports to shore up hull integrity.

Adding weight or bulk to a failing structure is never a good thing. Will only make things worst in the long run.

Need to address the structural flaw that is the root cause of the problem. Not put a band-aid the results of the problem.

 

[Watermann]

What else can be done to prevent it? I have seen spray rail braces added as well as additional risers and floor supports to shore up hull integrity. If you were me would you do these things? As of right now I am putting patches on 8 ribs that were slightly lifted. I believe the damage you have described was in its beginning stages with this hull. I did have a very rotten boat but the PO didnt use it much.View attachment 355679

With new decking, side panels, transom and new fasteners the risk of further issues goes down. Those areas of the hull have been weakened by work hardening as have the spray rail chines even though the areas haven't suffered a failure by splitting or cracking. That is why I added the braces to my Chief, so I would have no worry about catastrophic failure of the side splitting out.
Your boat can sustain rib some end cracking but if this happens, maybe not.