What material for Risers?
 

I am putting a new floor in my 1977 20 Seacraft Master Angler. Floor and risers look like water soaked untreated plywood. I am correcting the deck drainnage problem with through transom scuppers which will require me to raise the floor 2". My question is what material do people use for risers? I was thinking of using resin and some type of hardwood. Also, will 1/2 Marine plywood treated with resin and fiberglass be stiff enough for a floor in this boat ?
Thanks Jon

For the MA box stringers running some 2x4s cross wise will raise the floor. You could laminate plywood together outlining the box stringers to prefered height or even cover the whole stringer w plywood and laminate to height you want. I did the 2x4s on my last MA. Raised the floor 4" and worked out perfect. May want to go alittle higher since you are already raising the floor. I used 3/4. 1/2 can work but no more $$ 3/4 is I wouldnt go w 1/2.
Check out my rebuild on here under "parrott" and "seacraft84" usernames

What are you considering risers? The stingers? if so they should be solid fiberglass with foam in them if that is the case. No wood to rot there. Far as the deck 1/2 marine ply like douglass fir or such would be a good wood choice. Aquatech is popular as well. You need to make sure you get the fiberglass lay up right due to most of the strength comes from it and not the ply wood. The wood is just a core and adds some strength but the true strength comes from the glass lay up on both sides of it. Far as raising it up, parrot's 2x4 idea works well and many others just raise the box stringers up whatever height the want. The project boat I started this weekend had sections cut out of my stringer tops to refill with pourable foam so I will just raise mine cause the stringers need new tops any way. If yours are in good shape I would just add to the top of them with stacked 3/4 marine wood strips layers to you get the height you want or the 2by idea would work well too. You might want to check to make sure your foam in the stringers is dry first cause if it is wet you will have to cut the tops to get it out any how and that might determine the best way to rebuild them higher.

Stringer material
 

Thanks for the replies, this is my first Seacraft and first boat rebuild. The floor sits on risers, the risers sit on top of the fiberglass stringers, right? Hope my terminology is correct.
Do you screw the risers into the stringers or glass them on?
Hear are some pics of the floor before and after cap removal
Thanks again

The floor sits on a bed of putty on top of the stringers

That's what I was about to say. Big ol globs of potter puddy. No screws. That will leave a place for water to get in. Use resin thickened with cabosil. (Similar to original potter puddy) Run a thick bead and bed the floor down in it. If you use epoxy it will bond together well.

This is how I plan on doing the floor in my 20' cc. Billythekid did an awesome job on this one. Your stringers may be the twin wide ones instead of the quads but you can do it about the same way. Molding the floor section will make for a lot less sanding in the end vs laying the wood down, laying glass on top of it in the boat then fairing and sanding your brains out.

http://www.classicseacraft.com/commu...=18607&page=14

Wow!
 

I don't think mine will come out like that. What a great job! I did pull the floor up tonite and this is what I found, see pic
I am picking up 3/4 marine plywood tomorrow and will probably use the plywood to get the correct deck height.
Any reccomendation on which scuppers to use for through transom?
Thanks again to everyone replying, the expertise on this website is great.
Jon

That floor is nice but time consuming also. I just like the fact that running some ss screws in the deck is that much more secure. Done right u shouldnt have to worry bout water intrusion. And running the cloth from one side of the floor to other ties it in well. I know the three different floors ive ripped up came up pretty easy w just the potter putty.
Fish u could just take 2" strips laminated together and outline the box stringers to desired height. plus u will want something around the perimeter of the hull for the floor to rest on too.

I agree with the time consumption, I takes longer to mold a floor but you dont have to do all of the fairing and sanding to true it up vs screwing it down and glassing in place. You will spend time either way. I rather spend mine making a mold table vs sanding and fairing. It still will take longer doing the mold but I feel like it makes a better looking, truer, straighter floor.

Far as the screw thing, The screws hold well till water gets in around them and soaks into the wood. I have pulled several redone floors apart including the one I am working on now and it seems like there is always more rot around the screw holes. The top of the screws gets sealed well but you cant really get to the back side to seal the wood where you added it to raise the stringers. You can back them out and add resin then put them back in and that will help but you will not have the same waterproof as if it was left just bonded down with thickened epoxy. I have used screws in the past myself but have tried to stop doing it under the deck area...

Either way it will last a long time, The main reason I started doing floors this was is I dont like all the sanding and fairing.

More than one way to skin a cat! Thats just my 2 cents. Im not a pro so take it for what it is worth.

36 year old inner hull
 

I Finally removed the rest of the floor and now on to the new floor install. You were right about the Potter Putty(in the original floor). The last floor was unlaminated 3/4 inch plywood that was rotted. At least the inner hull looks to be in good shape. Pretty amazing after all the neglect!

Weight Distribution 20" MA
 

Can anyone comment on the set up and placement of weight in these boats?
Old set up
2 main batteries all the way aft behind and up against the gas tank(plastic), 3 car batteries for the trolling motor located all the way in the forward compartment.
Potential new set up-
3 trolling motor batteries located at same level as the gas tank(below floor) under the front of the Centerconsole and then the 2 main batteries on the deck under the centerconsole.
I would think the more weight located lower in the hull would be better?
The pic is of the old Battrey compartment located in the area about two feet infront of the transom below the floor.
Thanks Jon

Assuming your tank is in the stock location, and your engine weighs more like 400 lb, not 250 or less, then put all the batteries forward.

I have my 20 gallon tank and 2 batteries under the console in a 1975 20 foot master angler. I have 420 lb of outboard on the transom (100 HP 4 stroke main, 6HP 4 stroke kicker). Balance is OK that way.

If the weight is a bit too forward, remember where everyone will be when boating a fish- an aft corner. If possible, put too much weight forward. If you don't like it, put tackle or a livewell in the stern. But I don't think you will have to.

One more thing- don't put plywood in your floor. Use a real foam core if you can, or coosa. Or buy nidacore- premade from boatbuildercentral.com.

Barring that, then balsa core.

These are all ok for weight. The foam cores are lighter, as is the nidacore.

Balsa seems to be stock. It is strong, but it is wood. And it gets wet and rots.

Plywood is the worst. Heavy. Strong where it does no help. Grain orientation makes for a faster rotting process than balsa when you get it wet/ drill holes.

I think you should check out 3/4"-20mm nidacore first. With or without glass already on it.

Floor/weight distribution
 

Too late on the floor-I bought 4 sheets of 3/4" marine plywood($99 each), from all the reading on the site I thought 3 coats of resin on the bottom, then 1 layer of mat and one layer of cloth on the top, then paint with some type of antislip material mixed in. I do have a limit on how much I can spend here. I thought this was a cost effective decent floor.

Thanks for the response on the weight issue, with an older merc 115 she got up on plane with all that wet plywood and the 3 batteries all the way forward before so things can only get better

Inner hull
 

What would you do to the inner hull before putting the floor down? Would doing a quick prep and a coat of resin to seal things up? or just leave it?
Thanks again Jon

FS, is got a good tip on the composite foam. If you can afford it, foam is the way to go. Wood will last a long time if done correctly and if it is 100 percent sealed but the foam will last longer even if it isn't sealed well. Foam is defiantly a better product to put in a boat, but the cost becomes the factor when choosing usually. The cheaper wood may last 30+ years but you got the extra weight. I still don't mind using wood where weight is not a major concern but you have to take extra care and make sure it is sealed up well. Far as resale value, most people will pay more for a full composite boat so that is another thing to consider if you plan on selling in the future. I would not be afraid to use wood and I use it a lot myself, just take the time to prep it well and you will be good to go for a long time.

I was going to coat mine with a bilge coat product but read lots of bad things about it flaking back out. I ended up taking left over VE resin and coating the existing exposed areas. Once that dried and I was ready to cover the area I used interlux 2000e epoxy barrier coating to seal off the fiberglass to water proof it from any water that may get down there. Epoxy resin alone would work well and be better than polyester due to the water proofing nature of the epoxy. The polyester resin is porous and will not seal it as well.

If you have exposed fibers from grinding in the bilge, then a thin layer of vinylester probably can't hurt. Vinylester has good water and chemical resistance, works like polyester and has the elongation of epoxy (as it is partly an epoxy chemistry). Strick mentioned (and I agree) that an old school bilge coating is just gel coat. With or without duratec high gloss additive. It will stick to polyester or vinylester, but not epoxy. If you buy non-waxed vinylester, you can put this down, then coat with waxed gel coat over the top with no sanding in between if you follow up in a reasonable time frame. (Without wax, polyesters and vinylesters don't cure on the very surface- the air inhibits this. Most resins include wax that floats to the top to allow the cure on the side that sees air)

I am on a tirade against wood this year as I keep dealing with rotten stuff. But plenty of people use it successfully. So don't take my comments as that you did something wrong.

Merton's fiberglass in Springfield, MA is worth checking out if you haven't already.

If you want to use plywood, and you want it to last, I suggest laminating both sides with glass and use epoxy resin. Polyester resin is not impervious to moisture, and resin without glass in it isn't much better than paint, just more expensive.

Joel Shine, the moderator of this section of the forum, can give you good advice. His business specializes in boat kits with wood/epoxy construction. Done right, it's a good, economical construction method. Or you could post on their forum and ask for advice there (http://forums.bateau2.com/index.php). There are some good guys over there with experience in wood/epoxy that may be helpful.
Dave

It might be worth looking into vinylester for the same reason. It has similar mechanical properties in terms of elongation. And I suspect thinning with styrene monomer would be better than thinning epoxy with acetone, as the material properties should change less.

I can see if I can dig up a reference in my ASM handbook.

Polyester isn't as good, as it is more brittle. Which is why it sands nicely.

Ok, I'm confused. Why would you thin the resin?

To better soak into the wood? Sort of the opposite of bedding end grain balsa. But if you want to seal plywood, you want it to soak in before it gels, (I would think and have read.)

Just remember, free advice is worth what you pay for it.

I usually thin my Vinyl ester with styrene and do a good hot coat of thinned resin on the wood so it will soak up the resin better. The end grain especially. Once that is done and kicked a bit then I do the several layers of glass on both sides. If you dont hot coat the wood first the wood can pull (absorb) the resin out of you first layer of cloth and leave some air voids on the face of the wood and not bond as well. Wood will soak up a good bit and if you dont feed it first it will draw in from your lambent. You dont have to thin it but it helps. Just make sure you hot coat it first before you try to lay fiber down on it.

It is just like when you paint wood, the first coat usually soaks into the wood and gets adsorbed by it. The following coats will cover much better due to the wood is now saturated with paint from the first coat. Same with resin, the first coat will get adsorbed by the wood and even better if it is thinned. This helps for 1) to protect the wood against rot 2) to pre-saturate the wood so the resin used on the first layer of cloth dose not get pulled into the wood and out of the cloth. Wood will adsorb nearly anything - water, resin, paint ect. Better with a good coat of thinned resin deep in the wood pours to close off a path for water to get into latter.

50gal gas tank pushed up forward. Prolly the front was past the fishbox bulkhead a foot or so. Two batteries under console. Floor raised 4". Selfbailed good w 3/4 guys and baitwell under leaning post full. Raising it only 2-3" will not selfbail w people in it...trust me.
As far as wood. Makes boat ride better w the weight. These boats like weight and some big tabs that can keep the bow down. Couple hot coats of resin on bottom side is all u need. Especially using 3/4". All I used was two layers of 1.5oz mat on top of floor. Tabbed the sides of floor in w 1708 too. Unless u drill out all mounting holes in composite mess u will have holes that will not hold screws over time and also places where the glass gets compressed. We really dont know how composites will hold up over time cause it hasnt been used n boats that long. Wood has lasted 40+ yrs.....so why spend the extra $$. Honestly I wouldnt want a all composite boat. Why do u want a light boat for gas efficiency but will not ride good, which n effect will make u go slower, which means more gas and taking longer to get somewhere. Defeating the purpose of going light. Chances are it was not done properly and and the way I fish and whatnot I would have all the holes "wolard" out. Plus ive seen where the epoxy plugs put n where screws go pop out. Then.....wow....u have a mess on ur hands. What happens when the compsite breaks down from getting crushed and screws after screws being run in it. Basically back to square one and u have done spent a whole lot of $$ on the composite stuff. After ripping out the 1/2" floor in this 67' model that was just hot coated on the bottom I am totally convinced proper care and it will last. No rotten wood n the floor. Not one square inch.
As far as hull goes. No need to coat w any resin or paint. Just a waste. Unless u plan on keeping the bilge and hull full of water then u wont have to worry about the poly soaking up water. Actually u want the poly to breath so it can dry out when it doesnt have direct water on it. Plus ur never gonna c under the floor.
You can ask the guy who bought my boat and he will tell u it is set up just right. Cours3 it has the heaviest 4stroke motor, it still performs better then any seacraft him or I have been in . He is a member here and thehulltruth

Ok. I haven't done much with wood cores. Like you and FishStretcher, I prefer the foam or other inorganic cores. The only times I've used wood, I also used epoxy resin and I didn't have any problems with wet out or bond strength.

Thanks Parrot
 

I am making slow ground with an unheated garage in cold Connecticut weather, I flipped the cap Sunday-recruited my wife, father in law and fishing buddy. Glassed some spacers to the inner front hull to support the new floor. We had to reglass the top of the hull(someone used a sawzall on it?) to bring that up an inch and straight. More pics to follow.
Thanks again for the helpful posts.

Cap hull junction/? glass it
 

Thanks again for the input, I was wondering if what you thought, I have finished repairing the cap and hull and I will be reinstalling the cap this weekend. I am thinking of glassing the two together that way I never have to worry about a leak there. The only downside I can think of would be if the two needed to be separated for for a major repair?
Jon