83 Thundercraft Restore... Need some help!

OK... this might be a little bit but lets get started...

Ive read a TON of posts on the forums over the past yr but never really had impute to give out i guess. Hence my 1st post. So thanks for all the impute you've given me, cause it helps a lot.

1st off my boat 1983 Thundercraft Citation I/0 board with 4 cyl. OMC 3.0 ltr 165 hp(i think) motor. This boat was giving to me by a friend of mine who made me a deal on his camper and boat---Buy the camper, get the boat and $1500 worth of skiing equipment for free.. Nice deal only boat had the lower unit stolen off 2 yrs ago. Bought a new lower unit.. installed .. boat ran like a champ. Took it out 6,7 times last summer. Ok now the bad. DECK IS ROTTEN.. completely. Seats and vinyl are shot. Didn't know how bad it was until tore into it ...but i had my ideas. Time to start the makeover.



Here the boat is already tore down..Seats gone, deck a little opened up to see the damage, and the top cap loose.



Now the deck... joint in the 2 pieces of plywood caused the fiberglass coating to crack and water got in .. pretty rotten and still wet from last year


Took all the wires needed off, and drilled the rivets around the shell to remove the cap, then lifted in air to get it out of way.


Last pic is deck completely out and removed, and before I start sanding.


Ok now the rest of it.
I'm a carpenter by trade and have the ability to get this relatively quick back together. Money is always a issue, but can spend enough to get it RIGHT!

I decided not to remove the engine, and the supports under since of the work involved, and they are not rotten into. Just minor water damage, enough for a good week of fresh air and a fan would fix. Boat really needs to air out.
I will remake the stringers, and the deck. New seats i will make and my wife is going to upholstery them. New exterior paint job MAY get done, but we'll see. As noticed by the pics, no foam was installed in the boat for the deck. So now some questions for you all on HOW to proceed.

1.) Do i need to foam in the deck, in between the stringers?
2.) Should stringers have space(gap) 1/4" under them for give, or seal down tight?
3.) After fiber-glassing in the stringers, I was going to paint the btm of the new treated plywood deck, install , and fiberglass it down to the shell.
Thinking water-repellent paint would help w/ the btm of the deck?
4.) After drying of course, do i 2nd layer fiberglass in the bases for the seats or is another method easier, or better off doing-- I don't want the LAYBACK seats that were in originally, but just back to backs for driver/passenger.
But bases should be roughly same size.

Going to remake all seats and cushions, w/ new white vinyl w/ some type of pinstripe. Going with gray to charcoal carpet, and perhaps Candy apple red w/ silver paint exterior. Should look really sharp i think.

Thanks in advance for some input on this. I really am trying to get this up and back in 2 mths(in time for summer) and think i have a good shot at it. All the work thus far is only 2 days worth. Fri... 6hrs Sat.. 5 hrs.. so I think I have a good jump on it. Not trying to rush it, but just stay steady on the project. Going to let this week go by 3 days for the boat to dry out, then plan on sanding it down to get ready to fiberglass the stringers in place.

Re: 83 Thundercraft Restore... Need some help!

I would do some core samples of the transom and engine mounts. If there is any rot at all it has to be removed or it will spread to the good wood and you could be looking at redoing it again later. If the stringers were shot I have a hard time imagining the transom and motor mounts are still good. We have seen hulls twist out of shape because of the weight of the engine when the stringers were removed. The last guy I saw on this forum do it never knew till he went to put the cap on and it never fit. It only takes a few minutes to remove it now that everything else is out of the way.

Re: 83 Thundercraft Restore... Need some help!

Carpenter1 said:

1.) Do i need to foam in the deck, in between the stringers?
2.) Should stringers have space(gap) 1/4" under them for give, or seal down tight?
3.) After fiber-glassing in the stringers, I was going to paint the btm of the new treated plywood deck, install , and fiberglass it down to the shell.
Thinking water-repellent paint would help w/ the btm of the deck?
4.) After drying of course, do i 2nd layer fiberglass in the bases for the seats or is another method easier, or better off doing-- I don't want the LAYBACK seats that were in originally, but just back to backs for driver/passenger.
But bases should be roughly same size.

Click to expand...

1. Not necessary but highly recommended. Do a search here and you will see that people use foam board, pool noodles or two part foam and it is all a matter of safety.

2. The stringers should be bedded and not directly on the hull...... only talking about a 1/4" so there are no hard contact points ..... once again search this forum.

3. Water repellent paint is useless. Use fiberglass and csm to seal the plywood for the decking on all sides and edges (all surfaces). Use exterior plywood and no need for marine or pt plywood.

4, Install the seat bases the same way you would blind shelving brackets.

Investigate your transom and engine mounts VERY carefully. Chances are you have work to do there too. Boats usually rot from the inside out and it is like cancer and spreads like wildfire!

MOST IMPORTANT........... Welcome to iboats!!!

Re: 83 Thundercraft Restore... Need some help!

The engine mounts look good, only real MINOR water stains on the edges down toward btm of hull where the stringer was mounted originally located. Surface is alittle soft but SOLID otherwise. And as for the Transom... i believe that is the 3/4" piece of plywood mounted right to the back of the boat? ... only where the old stringers were butted up to it, is there any soft spot, but again completely solid otherwise.

The engine mounts to what looks like a 4"x4" solid beam on both sides. If i were to take it out, how to approach it. And finally how to get the transom out. But again I think they should be ok. The old fiberglass held in place back toward the back of the boat preventing the damage that is up front and mid.

Re: 83 Thundercraft Restore... Need some help!

I went up this afternoon and sanded the boat hull down.. grinded more like it. What a chore that was. I went ahead and took 2 pics for some to look at for the engine mounts and the lower main stringer. Both pieces were really solid and looked good after drying out just for a day. Tell me what u think plz.

Also if you look closely in the pic below the engine... the top of stringer has crack in the fiberglass i will need to address. Need to recoat and check this area.. but need some ideas on that part.

Re: 83 Thundercraft Restore... Need some help!

The stringers, transom and motor mounts all work together as the frame of the boat. The transom is soft where the stringers attach to it. There has been water intrusion to your motor mounts. Letting them dry will not stop the rot, change them out. Why go this far and then try to cut corners on 2 very important sections?

Re: 83 Thundercraft Restore... Need some help!

I think you might have misunderstood me. I did inspect the transom and engine mounts only to find they are very solid and very stable.
The drying out statement was just a general observation from when i tore into the boat. on how diff things look.

I think that I might have gotten lucky on the transom and mounts. Ive seen ALOT of wood rot over the years in construction and I dont think in this case that it has eaten into those parts. But your right on the seriousness of the parts. Never do i want to cut corners.

So I say thanks for reminding me to inspect them thoroughly. Since this is my 1st boat and 1st restore.. I NEED THE HELP!!

Re: 83 Thundercraft Restore... Need some help!

Carpenter1 said:

Surface is a little soft but SOLID otherwise. ... only where the old stringers were butted up to it, is there any soft spot,

Click to expand...

I don't mean to question your expertise with wood as I'm sure it's far greater than mine but these 2 lines were taken from your posts. For the amount of time it will take you to replace these sections I would redo them myself. Peace of mind kind of thing knowing all the wood is new and sealed better than it was when it was a new boat. Do a search on transom repair or replace and you will get more info that you can possibly need. Some guys use dimensional lumber for stringers but the more experienced members here will not use it. Plywood will give you the most strength. It needs to dry out so get what you need and give it time to dry. Some use pressure treated but because of the problem they have with it eating fasteners, most leave it alone. Remember the engine should be removed so the hull stays straight.

Re: 83 Thundercraft Restore... Need some help!

so if I put new stringers in with the engine still mounted will i warp the hull?
guess im confused on that part.

Re: 83 Thundercraft Restore... Need some help!

I would say that there is a possibility....I didn't have a motor on mine at the time of restore so I never had the problem to consider....
I would rather be safe than sorry!!

Re: 83 Thundercraft Restore... Need some help!

With the stringers in, the weight of the engine was distributed throughout your hull, now it's concentrated in that small engine mount area. The boat is on a trailer and the hull is only supported in a few small areas. Once you removed the stringers the weight of the engine can buckle or twist the hull. Once you install new stringers and attach them to the hull,transom and engine mounts they will hold the twist in place. It only needs a small twist in it before the cap won't fit. If you remove the weight of the outdrive and engine,the chance of the hull being bent out of shape while you work on it is greatly reduced. You are replacing the frame of the boat. Doing it with 700-1000 lbs still in the hull will most likely cause you problems. It needs to come out.

Re: 83 Thundercraft Restore... Need some help!

guess that makes sense to a point .. however that engine is the old OMC motors with the rubber boot in the back... THE worst engine to take out.
Hate to take the engine out when im back to deck and carpet in a couple of weeks.

Also we dry fitted the cap back to check the hull and still looks good and straight, and whether it makes a difference or not but the straps and pulley is still holding the hull down so i hope that makes a difference on helping the hull stay straight.

Thanks for the input on this

Re: 83 Thundercraft Restore... Need some help!

Know what if the stinger is rotten where the engine sits at but the rest of it from there to the front is still good how would I replace it 13 inches that is rotten