Deck replacement and hull repair job

[devonstern]

Hi all. This is my first boat, first project. I got this 17 foot half cab as a partly commenced project, that obviously had a rotten floor, which had been ripped out. The previous owner stopped there. I have been reading up on the excellent thread by Oops about the hull extension project - awesome!
My plan is to: repair the hull, put a new deck in, fully prepare the hull and superstructure for paint (or do it myself if possible), try to get the motor going, or find replacement , put some seating/storage space in the bow, have fun on the water..
The Transom, and stringers are in good condition (luckily for me !)
I have a few things in mind to get started.
1. I'm building an engine stand to take the '78 blueband Mercury 800 out.
2. Then I will strip everything off the boat, controls, wiring, windscreen, nav lights, windows etc.
3. I'm going to take it off the trailer and trash that old hand made job, putting the boat on tyres, then a rolling cradle set up I saw on the above mentioned post. (should I leave the superstructure on top?)
Before I start the deck, i need to do one or two repairs, and need some advice. When cutting the deck out, the last owner put a gash with an angle grinder through the hull, about 4 inches long. Do I cut that into a square shape, glass from the inside with an overlap onto the existing hull, and fill from the outside? The area its in is a curved section of the hull. That's my first question - trying to attach a photo now through photo bucket, as Oops suggested. Sorry if it doesn't work.

 

[Woodonglass]

Re: Deck replacement and hull repair job

Welcome to iBoats!

What have you done to ensure that the Transom and Stringers are "Good to Go" ? Have you core sampled them?
As for the cut, Acetone the outside and inside of the hull. Use packing tape to tape over the cut from the outside. Grind then inside of the hull all around the crack about 3" all around the crack. Acetone it again. Fill the crack with thickened resin also know as Peanut Butter. Lay increasinyl larger layers of CSM and 1708 Biaxial cloth over the crack. Two layers of 1.5oz CSM and a layer of 1708. It's fixed. On the outside You will sand, fill with fairing materil and either prime and paint or gelcoat depending on what you decide to do with the hull. If the transom is indeed good to go then there really is no need for you to remove the top structure from the boat unless you intend to flip the hull to do repairs on it.

 

[Yacht Dr.]

Re: Deck replacement and hull repair job

Welcome to Iboats Devon .

I would grind/bevel/feather the outside of the cut. Prep the inside of the repair. Duct tape the inside. Layup the outside with poly and some mat and 1708 until you reached level/fair ( It doesnt look like its that thick so it wont take much ). When that cures go back to the inside .. peel your duct tape and apply a few layers of mat and 1708.

You can sand smooth the outside whenever you like during your project.

Hope this helps.

YD.

Edit: Woody beat me to it..but I have a slightly different approach .

 

[devonstern]

Re: Deck replacement and hull repair job

Thanks guys - to answer you question Woody, all can say is a had a bloke from the local marine shop come out and inspect the boat. He used a fairly un-scientific method of tapping the stringers and transom. I now know that probably isn't too reassuring, but previously I was relying on the word of an experienced repair man. The stringers, you can see they have been laid up really well by hand and I reckon they're ok.
So - as to taking a core sample, how is that accomplished? I might as well do it yeah - although I'm scared of what I might find, I feel reassured that I can find the direction I need from this site..

I sort of like Woody's approach to the repair job - but I'm not really sure what peanut butter is, or rather, can I have some directions on how to make it?
Also, with the boat came two rolls of glass. Not knowing much about glass I don't know what the different types are. When you refer to Mat, do you mean CSM? The material I have sort of falls apart if you play with it too much, is that Mat?

I played with the idea of flipping the boat, but I think it might be overkill, and turning it on it's side would be enough.

Anyone have easy directions to build a cradle? I was thinking make a template out of cardboard, and cut two pieces of ply in the shape of the hull, joining them for strength, and attaching that to a base of some description.

Thanks again

 

[devonstern]

Re: Deck replacement and hull repair job

Yeah, so I decided to get started, and I'm sure I can find out what ratios of materials I need for peanut butter no probs.
I'm guessing I should just drill in to the transom perpendicular from either the outside or inside. I'll go for inside I guess, as it might be easier to repair and cover over later... drill one high and one low in each side should do it.
I'm worried though if I find rot about this glassed in seat section, as in how would I get it all back together.

So - I decided I needed an engine stand - got that done today.

Then - I pulled apart the forward control box, and disconnected the shift assembly - also to see what the wiring looked like inside - not bad.

Ripped out all the wiring - boy the PO was not real fussy about anything, more electrical tape than anything else, nothing protected from the weather.

Then I pulled four bolts out of the flywheel to attach a lifting plate to.

Once I disconnect the steering, she's ready to rip off the boat. More to follow..

 

[devonstern]

Re: Deck replacement and hull repair job

The motor itself looks surprisingly clean, and free of rust. I have no idea if it runs, or when it last ran. At the price I got the boat for - $200 - I wasn't really worried about it.

Couple of eroded wires, and a worn out earth strap. Bet it needs a carby kit through it. Well, I'll worry about that once I get the boat itself sorted.

 

[glenn property of pam]

Re: Deck replacement and hull repair job

looks like you are having fun. compression test the motor and start a tread in mercury motors if its lower than 100 or if there is more than 10 psi between diffrent cylinders the guys there will help with any motor problems. the pb mix is a little fluid the way i make it is to put resin in a cup then add the hardner and mix for at least a min then add chop till it looks slimy then add the bubbles until i get it thick enoght that the resin does not run of the end of the mixing stick. main thing to watch is that all prework is done before you mix anything. nothing worse than having a mix starting to cure and then having to wipe the area with acetone. drill test holes from the inside of the transom and you are only breaking the fiberglass skin so 1/4" is deep enoght. on a small area like the cut you will find that a brush works on the csm then dipping the 1708 or putting the 1708 on plastic and putting resin on the back first will ensure it soaks out easy. 1708 is nice to work with as a newby as it can be handled wet the csm can be a pain when wet and will tear real easy or follow the brush so its more of a tapping than a painting action on that. cut all the glass to size first as you will not have time once the resin is mixed. if it was my boat i would test ducktape over the cut to see if the skin flexs then consider putting 1" wood either side of the large cut once ground out 90 degrees to the cut with 4" gaps to act as a brace to keep the skin in line then csm the area between the wood then when the wood is removed the skin should be strong enoght to stay straight or as you put pressure when applying the mat the skin might flex and that will cause the mat to try to fold. you can not realy go wrong as anything can be ground out and redone. have fun

 

[devonstern]

Re: Deck replacement and hull repair job

Thanks Glenn - all good suggestions. And really helpful advice about working with glass. I'm almost ready to start repairing the cut in the hull.
I think i will start a motor thread a bit later on. As for the chopped strand to make PB, can I just get some of the matting I have and roughly cut it into, say 1/4" lengths? I saw somewhere one of the ingredients was Cab 0 Sil - what's that?
Cheers.

 

[glenn property of pam]

Re: Deck replacement and hull repair job

cab-o-sil is ........ no idea.....its like a white powder kinda stuff. i have a big bag and no idea what it is or what its made off but it works to thicken the resin lol
to be honest your hull is proberly so thin that you wont need any great amount as you are only using it as a filler you will need some 1708 and you should be able to get that at any boat place as this is what gives it strenth. ask at the boat or fiberglass place and they might have a premix cheaper for the small amount you need (the surgestion is to use it as a sandable filler not as a structal paste so a thin layer in the cut is pleanty as the csm and 1708 is what will hold the boat together).
the picture is from the inside looking out of the boat?
i have read about people using chopped up mat and talc but i do not have the experiance to decied if thats a good or bad thing i know people on here do not like marine bondo and would rather use pb.

 

[rickryder]

Re: Deck replacement and hull repair job

To do core samples you take a 1/4" drill bit and drill into the stringers near the mid-bottom and check the shavings....damp dark wet ...no good.....clean white dry ....good. Same thing on transom, just only drill in about 3/4" DON'T drill through the outside.

 

[devonstern]

Re: Deck replacement and hull repair job

Thanks Rick, thanks Glenn.
The pictures of the cut, the first one, with my hand there, is from the inside, the second one, with my finger is from the outside. Yeah I agree the PB will be like a fill job, and the glass on the inside will provide the strength.
Fingers crossed - I'm going to sample the stringers and transom on the weekend.

 

[devonstern]

Re: Deck replacement and hull repair job

So, I couldn't get time to spend on the boat last weekend. Today, I finally got the motor off. Included some pics here of the job.
Got the lifting ring finished, disconnected the steering. I didn't have a block and tackle so had to improvise with a lifting device.
I just removed the hand winch from the trailer and bolted that to a beam in the roof of my garage - worked like a charm.

The finished lifting ring

Bolted it on to the motor with some longer bolts

The winch serves another purpose..

Hooked her up , and off she came, just like that.

Now, I can clean up and get to the areas I want to inspect before I start the real work.

Then - almost a disaster - I was pushing and pulling the trailer and boat around my yard, when the mounting bracket for the jockey wheel broke. It caught my finger between it and the draw bar momentarily. I was VERY lucky not have been injured worse than this..

So - I packed up the tools. Live to fight another day !!