Help with '75 18 ft Seacraft project
 

I am just getting started on my 1975 18ft seacraft. I am competely redoing everything. New floor, stern, paint, gelcoat, and motor bracket. I will try to post some pics of the progress from start to finish. I am going back with all composite material and I ordered an aluminum bracket w/swim platform. My brother-in-law is a very experienced fiberglasser and painter but I may need some input when it comes to mounting the bracket and motor. I was wondering if a 115hp motor would be sufficient for my boat. I am closing in the stern and the bracket I ordered has a 26" offset. I'm not sure how high to mount the bracket or if I will need a 20" or 25" shaft. I have tons of questions as you might would guess. I have a t-top and leaning post that came with the boat when I bought it which I love, but I'm not sure how to position it in the boat to make it where it is not stern heavy. This is my first seacraft and I like the potter hull design. I have never ridden in one of these boats but everyone I talk to say it is by far the best mono hull boats money can buy. Any input on horse power, setup of console, and bracket mounting would be appreciated. This is a great website and look forward to talking to some of you about your trails and tribulations that may save me the headachs that I am sure alot of you have already been through and learned about the hard way. Thank you for your time.
Adam

Re: Help with '75 18 ft Seacraft project
 

I had one with a 115 inline Merc and it was fine, no T Top and on rare occastion I wish I had a bit more but it really was pretty fast - I am a gear head. Keep in mind those motors weighed in at 268 I think too, so weight is the biggest issue especially if you use the infloor baitwell. With the heavier motors today I would think about a baitwell under the leaning post. If money is no object a 115 HO Etec would be perfect as its 4 cylinder.

Re: Help with '75 18 ft Seacraft project
 

my 77 18' has an older 120 omc, and it has ample power. my 75 18' has a 150 yamaha, and it has more than ample power. i would think a newer 115 would be a good choice. especially on a bracket. i would do away with the in floor live well and build one into the front of the console. i was going to do this on my rebuild but ended up using a newer mako console with a 20something gallon live well built in. my boat rides great when it's full. i also have a 12 gallon secondary well in the transom but i mostly just use it for a trash can :D

Re: Help with '75 18 ft Seacraft project
 

Thank you for the input. The stern weight is one of my biggest worries. I have removed the infloor baitwell. I am thinking about putting it in the box seat in front of the console. I think the specs said the dry weight of my boat is around 1400lbs. I am taking out every piece of wood in the boat and replacing it with pinski board. It is about 1/3 of the weight of plywood and just as strong. So I would expect the over all weight of the boat would be reduced considerably. The gas tank had been replaced but who ever did it did a shotty job. All the wood over the tank was rotten and water logged. The stern was also very bad. I am also going to grind all the wood out of the gunwales and replace it with composite. The previous owner had a 100hp yamaha four stroke on it and said it did fine. I would think it would be very bad on the hole shot with that motor, but I could be wrong. Those motors I am pretty sure are over 400lbs. The bracket I am getting is positive floatation so I am hoping that will help with stern weight at least at a stand still. I was wondering if anyone had done anything with moving the gas tank forward to compensate for the motor being an extra 26" off the back of the boat. Seems like it would help but I dont want to do anything that will hurt the performance of the boat.

Re: Help with '75 18 ft Seacraft project
 

Re: Help with 18' SeaCraft Project
 

With your concerns for balance and stern weight, which I agree with by the way, I would highly recommend a Hermco bracket because they have the most flotation. Don said he can make them with various setbacks . . . 18", 24", 30". The 30" is nice if you're a diver, but otherwise you could use a shorter one, especially if you pick a V-4 motor. Also if you're boating in salt water, you won't have to worry about corrosion issues with it.

Re: Help with 18' SeaCraft Project
 

Yeah I would love to have a hermco bracket. They are extremely nice. I do have some budget issues and had to order one I could afford :(. One day if I ever find a good 23' seacraft I might look him up to make me one for that. I am hoping with a lighter v-4 I can get by with the cheaper aluminum bracket. I looked over all the pics on the hermco website and I like the water tight fittings for the controls and steering cables. Does anyone know where I can order those thru-bracket fittings :D.

Re: Help with 18' SeaCraft Project
 

Here is a link to pictures of my 18 that don at hermco did for me http://hermco.net/gallery-2.htm

Re: Help with 18' SeaCraft Project
 

If it were me I'd save some money by using balsa core instead of Penske board or whatever in the deck and put the savings in the bracket. (Balsa core works fine, but as with any cored structure, you just have to properly seal any holes in it with the drill oversize, fill with epoxy & redrill routine.)

The hydraulic steering hose fitting is a Cable Clam which is available from West Marine and other marine supply outfits. It's just a tapered round rubber plug with a tapered plastic ring on outside. Just drill the size holes needed for hoses in rubber plug and then cut the plug in half on centerline of holes. With a little silicon around the hoses, the tapered ring keeps everything in compression and water tight. I've also seen metal fittings for hydraulic hoses that go thru a bulkhead where you connect a hose on each end. Makes for a neat installation but it adds 2 more hoses and 4 more connections which are a potential leak source. Advantage is that when UV finally kills the hoses, you only have to replace 2 short hoses instead of the long ones all the way to the helm!

The fuel line/control/electrical cable rigging kit is probably available from numerous supply outfits, but I got it from Don for about $45. I like the way he rigs it down into the bracket and then into the transom inside the bracket because then you can walk across the platform w/o having to step over all that stuff. Kit includes 2 aluminum tubes, about 2" OD by about 4-6" long, and 2 flex hoses and clamps that fit over the tubes. If you're having an aluminum bracket made up, you might want to have the vertical tube welded into the bracket so it's coated or painted at same time as rest of the bracket. Also, after you put the tube thru the transom and run all the rigging thru it, fill it with silicone. It's probably below the waterline, so if you ever develop a leak in the bracket tank for whatever reason, you don't want that sinking the boat!

Re: Help with 18' SeaCraft Project
 

Thanks vcsjupiter for the link that is a very nice setup. I bet she will fly. Can you tell a huge difference in the performance of the boat while underway with the bracket? How much setback is your hermco bracket? Do you think I will need to have trim tabs on my boat for any reason?
Thanks


Thanks Bushwacker for the info. If I understand correctly I need a tube welded in for the throttle cables,wiring harness, and power cables to go thru then a sleeve goes over all of it to the motor and it secures with a clamp around the aluminum tube that is welded in. Sorry for all the questions but on this website everyone is so helpful even with my stupid questions. Thanks again.

Re: Help with 18' SeaCraft Project
 

Adam yes there is a huge difference in performance, i went with a 30in setback on the bracket, I went with a doelfin instead of trim tabs and it rides great.
Tony

Re: Help with 18' SeaCraft Project
 

Adam, like I used to tell the guys that worked for me, no such thing as a stupid question . . . only stupid mistakes!

Your understanding of the rigging tube assembly is correct, assuming you want to rig it like Don Herman does. You could just drill a hole in the bracket and secure the tube with epoxy, but if you're having one made up, seems like it would be cleaner to just have one welded in before they powdercoat or paint it. You'll still need a smaller hole for the hydraulic steering lines.

Regarding trim tabs, I use them primarily for lateral (side-to-side trim). A deep-V will tend to lean into the wind; the wind blows you off course, so when you crank in some rudder to correct, boat will roll in the direction you turn the helm. When you lay a deep-V on it's side, it's NOT a deep V anymore! When waves are coming at you at some angle off the bow, rolling the boat just a few degrees AWAY from the waves with the trim tabs increases your deadrise relative to the waves and will create a big improvement in the ride! You can do the same thing by moving gear or crew around, but the tabs are more convenient. I also use a Doelfin for fore & aft trim, and on a 25" motor on a bracket, it makes a big difference. Also if you're stern heavy, a 4 blade prop will also give you some stern lift.

Re: Help with 18' SeaCraft Project
 

Yeah. Usually caused by not asking questions in the 1st place.

Excellent advice!!

Re: Help with 18' SeaCraft Project
 

Thanks for answering all my questions. I found the cable clam fittings and also found a few rigging tube kits. I need to get one of those even if I get the tube welded into the bracket so I can use it thru the transom.

As for using balsa core instead of penski board......I am pretty set on using the composite just because I know I will never have to worry about anything after that. I helped my dad redo his skiff a few years back and he used the composite. It is some of the easiest material to work with and as soon as you glass it, it is there for life. I know it might sound like I'm hard headed on this part of it, but peace of mind goes a long way. It is very very light weight as well. Anything I can do to make the boat a little lighter (especially in the stern) the better. Anyway, thanks for all the input so far.

Re: Help with 18' SeaCraft Project
 

I saw some bottom paint remover in west marine the other day and I was wondering if anyone had ever used any of this before. It says it won't harm the gelcoat. Also can anyone tell me what the best thing to get to clean some oxidation on my aluminum t-top. I want to try and make it shiny again. Thanks.

Re: Help with 18' SeaCraft Project
 

Who would have thought echs class of 2000 would have two seacraft fans :)

Re: Help with 18' SeaCraft Project
 

Whats up Tyler. Yeah I bought a seacraft and am in the middle of redoing everything. You will have to come take a look at it sometime.

Re: Help with 18' SeaCraft Project
 

Hey man were did you get the penske board and let me know what your doing about the live well.I'm thinking of getting rid of my livewell too its a pain in the ***.Dad had an 18 when I was a kid had lots of fun in it.

Re: Help with 18' SeaCraft Project
 

I am not putting the live well back into the floor. I might put one in the seat in front of the console or a small one in the new full transom. Not sure if I put it in the transom it might add to much weight right in the stern. My brother-in-law ordered the penski board for me from somewhere, I'm not sure. What size motor did your dads have on it. I am trying to decide what I need to look for.

Re: Help with 18' SeaCraft Project
 

Dads boat was I think an 1986 or 1987 with a 150 mariner.I want to say close to 50 top end.The only reason I remember the year is a guy my dad knows got a 20 the next year it was a tracker model like mine I think 1987/88 was trackers first year.I believe I read that somewere when I was looking at my boat.Anyway I remember dad racing his buddy in the 20 with a 175, dad beat him.My 20 had a 150 yamaha on it 2 stroke it self bailed fine had good power to.

Re: Help with 18' SeaCraft Project
 

I'm no expert but I don't think a small livewell in the stern of the 18 with a floatation bracket and a 130 2 stroke or something like that would not hurt.It's your boat but a set of tabs is a great thing to have.I am Going to get a set this winter if it's the last thing I do.

Re: Help with 18' SeaCraft Project
 

One more thing. I dont have a closed in stern & bracket but the new four stroke 465lbs. or somthin close and the above deck 30 gal livewell full in the stern is 2 much weight.Since i have no tabs I have to trim engine up and down to keep from loaping and in the ocean this still sometimes isn't enough.Also you might want to raise your decks a little.My 20 with the big engine and the well full will self bail if i'm not in the boat.That to me is not that big a deal as I mostly live bait cobias and trout flounder and other inshore stuff so i just plug the drains.But in the ocean I would want to be able to keep them unpluged if there was any kind of sea.I admit that i plug my scuppers and go in the ocean all day but its nice to be able to get water out quickley and I dont like pulling plugs every time I jump the boat on a plane.

Re: Help with 18' SeaCraft Project
 

I probably should be fine with putting a small livewell in the transom. I am going to raise the floor about 1 1/2 in. Plus my drain holes are going to be out the side of the boat in the corners. That will make them that much further out of the water. Keep your eye open for a real good deal on a outboard 115 - 150 hp. I'm going to get a used motor for now and maybe upgrade in a couple years. We just got the materials in this week and I am going to get started on it hot and heavy in a couple of weeks. Just have to balance work, boat rebuild, and most important, hunting. Its a tough time of year to be working on a boat.