Refinishing Hull

I never took any pictures of the actual cracks but I will go through my pictures and see if I can show you where they were , what I have done so far .

 

very good thank you so much
the types of cracks and the shape in relation to the hull is quite important and could say what is the problem !!
Boat size ?? do you know the hull laminate structure at all ?? how was it built ?? Pictures of inside of the hull could be valuable as well bulkheads and stringers etc etc !
THE MORE INFO THE BETTER WE CAN ALL HELP !!
no video please is always shaky and detail is missing and never see anything so is a waste of time and effort !!

 

Stress cracks

Hello Tunnels, I have been busy doing other things at the moment but have some time to show you where I am at. Basically I have gutted out the interior as you can see in this photo



I replaced the stringers etc tabbed them in starting with 1.5 mat then a layer of 1708 then mat t then a layer of 1708 So 2 layers of mat and 2 layers of biaxial. This lay up was used on all bulkheads and stringers.Alot stronger then factory.Then I poured in expandable foam. I have not finished the deck yet as i want to do a one piece layup inside after I have everything in place. Right now the deck on the sides has 1708 on top to seal it.

When I was taking the boat apart the poor workmanship was not long showing itself.

In this photo



I outlined in red apprx where I found stress cracks. There was 3 side by side on each side starting from the front of the stringers towards the bow about 12 inches long. There might have been a couple smaller ones a little higher on the bow towards the bow hook.

Like I said earlier none of these were structural and only in the gelcoat and chopstrand layup layer. after i removed these layers they were gone.

Getting back to the workmanship the first 6 inches of the main stringer where the stress cracks started was not even tabbed in from factory. They just had a little bit of chopstrand sprayed there. Also in the first photo you will notice the area I have shaded in in black over the ski locker. The phot never worked out but it is the compartment closest to the bow.This area was not even tabbed in along the bow of hull. Every boat I have seen around here the whole deck is tabbed in.

That being said I think there is too much flex in the bow of the hull . I was thinking of tabbing in the deck up in the bow , because right now I can push in on the hull just above where the deck should be tabbed to the bow. So on the lake hitting a good wave i can see it stressing enough to crack the gelcoat in these areas which I have showed in red in the second picture. Basically a problem with poor stringer tabbing and deck should be tabbed in would help stop with some of the flex. the piece of decking over the ski locker was only held in by a 4 screws, so the hull could flex pretty good if hit hard enough .


This is a 18 ft bowrider. As for hull thickness the sides are not very thick to me but I know the bottom had a 5 laminates plus the chopstrand then gelcoat .maybe 1/4 inch thick. I repaired a couple beach rashes.The keel is pretty thick .

But my biggest concern is I would like to strengthen the hull to replace the chopstrand I took off or maybe just strengthen it because i feel it needs it especially in the bow.

I don't need to go to thick and add alot of weight. I know the chopstrand and gelcoat in the bow area i took off was not an 1/8 of an inch but along the bottom the chopstrand itself was around an 1/8.

I hope I explained myself and Thanks for any info

 

Well the boat builders from the island dropped by on the weekend. They were very impressed with my work and the procedure I wanted to finish with. I told them that I wanted to put a layer or 2 on the boat to replace the chopstrand I took off. They suggested that since chopstrand does not really have any strength or structural significance. That I could go with either 2 layers of 6 oz cloth or 9 oz s weave to add a little structural strength without adding much weight. They realize that all I want to do is to seal all my repair work into one layer to protect it in case of another hit on the hull. Instead of hooking on a repair this layer might save it. The stress cracks they said were in the gelcoat layer so good to go. They had the same opinion I had that if the deck was completely tabbed in along the the bow it would have stopped the stress cracks in the gelcoat. Anyhow got some landscaping project on the go. Will get back to this next month.

 

Hello Par it has been awhile, but I am back at it. The epoxy I am using has a pot life of 20-25 minutes and a set time of 3-4 hrs. The drying time is 8-10 hrs. I was rough fairing last night and mother nature gave us a wicked storm that was not called for. So basically I missed my time for applying some more fairing material where I wanted to put multiple layers. I was told not to epoxy in the rain so I decided to leave it. How soon can I wash down my material to make sure there is no amine blush before I add some more material. I was also wondering in all the guides I read they say to put a fresh coat of epoxy over my existing fairing material and let gel up before I add more fairing material. Is this step actually needed even if I just roughen up the fairing material for the new stuff to bite too. Thanks for all the help and great ideas.

 

Wait until the rain applied goo is good and cured, then wash with warm water and a mild soap. I usually wet sand in the process (adding tooth), killing two birds with one stone. As to how soon, well if you can't press a fingernail into the goo, leaving a dent, you can probably start washing and toothing.

You can over coat fairing compound, with more fairing compound, without a straight epoxy "tie" coat. Make sure the previous fairing compound has a good tooth (I use 100 - 120 grit), so you get a reasonable mechanical bond. Once you're finished with the fairing and smoothing process, it's always best to over coat the filler areas, if not the whole hull with a thin coat of straight epoxy, which seals things down. This provides a sealed base for primer.

 

Par Thanks for the tip on the killing 2 birds with one stone working great and a lot less dust

 

Fairing Compound

Hello Folks I never abandoned the project just took a break. Well I realized after I started taking the gelcoat off there was no turning back. I finished the repairing of the stressed hull near the end of July. Got the laminate in the shape I wanted before I jumped into actual fairing.

I am now at the stage of actually fairing the hull and getting my lines back. I am finally seeing progress with this hull. I actually feel good after I put a little fairing compound on one day and use my hack saw tool to shape the next day. Only have a couple days at this so far.

Here are a couple pictures of where I am. Like I said I am just starting to fair and shape to get the design of the hull back. I am inpressed as you layer the fairing compound and begin to remove the compound, the lines and kicks in the strakes or chines actually come back with a sharp edge rather then the rounded I had after removing the gelcoat.. I know I need a few more light coats of faring compoiund but what I am seeing is making me happy.

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This is my little hacksaw shaping tool

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I drop in now and again ad read post from all the experts. I really appreciate all the advice from all to get me this far. I feel I am on the down swing now. I know I have alot of work to do but it just seems easier at this point.


Thanks

 

hey im new to this forum and have a few questions. first im looking for a project boat and have found one. the only problem is its been sitting on the ground for a few years with water in the engine compartment and cabin. i would like to know your opinion on what to look for as in hull integrity and how bad do these wooden fiberglass boats degrade over time. the boat is free just have to get it home if i want it so great project. The boat is around the 70's and is a 24 ft chris craft stern drive with small cabin. would appreciate your input thanks.

 

main concern is wood rot and if a few years sitting in water would completely ruin the hull. just wondering if it would be ok after it dries out. i know this isn't something u can really answer without seeing it for yourself but would like some professional opinions. i will be inspecting the hull and taking more pictures this week. so ill have some to post on here for help. thank again

 

and what would u think of changing a stern driven boat into a outboard. so i can convert engine compartment into live well.

 

and plz direct me to the correct thread if this one isnt a good place for these questions thank

 

Welcome to the forum marine.

You'd be best advised to just start a thread of your own, with some pictures and a better idea of what you're dealing with.

Yes, you can usually convert an outdrive setup to an outboard, with few difficulties.

 

Well Hello Again, It has been awhile

Have a question on a problem I have come across while doing the barrier coat. I have put down 3 straight coats of resin and used a new foam roller for epoxy each time. One for applying and one for tipping. I was going to do my last 2 layers with a pigment added. Well I was applying the first pigmented layer and was watching the usual bubbles appear . Then I would clean them up with my dry roller. Well this time around the little bubbles had pieces of foam scattered. Not big enough to pick without making a mess.

I don't know if the pigment reacted to the roller or i had a bad roller this time around.

I am going to let it harden as I was trying to do hot coats. I am just wondering since this is in the barrier coat,

Do you think I would have to sand the foam out until it is gone down to the previous layer of epoxy or do you think it will set up and I can knock the foam off before putting on another pigmented layer?

I am just doing the barrier layer right now and still have to prime for my final prep for paint.

Thanks

 

Welcome back.

A hot coat (temperature) will not help anything and is only used on raw, porous substrates (wood mostly) to prevent out gassing. Or do you mean green on green as a "hot coat"? If this is the case then you're correct to take advantage of the chemical bond, with a green on green technique.

Yeah, it sounds like a bad roller. If you can knock them flat once this coat is cured, you'll be fine, though put an extra coat on, because of the aggressive sanding you'll have to do to smooth out the pesky roller hunks.