Stringer Templates

82 Nautique 1 wrote: Started my project today... Wow.. Has anybody added additional alluminum supports under the wood seating area for support? I would think something could be made similar to the engine cradle.

I really don't feel this is needed nor a good idea. First, the wood for the seat support is plenty. The problem with the factory design is it got wet. With your epoxying the wood, this shouldn't happen. Second, if moisture did somehow get down there, I don't feel the aluminum would survive very long - white rust! Stainless wouldn't even like it. It needs to dry out occasionally to maintain the oxide barrier. The difference with the engine cradle is it's out in the open. Third, even though the bolt holes going through to the aluminum should be sealed with 5200, it's a potential leak.

BTW, any fasteners going into the floor should be pilot drilled, CPES's, epoxied and then when driving the screw, 5200 sealed.

If you want to beef up the floor at the fasteners, epoxy a extra layer of wood on the bottom like a 1x2.

Sorry, here is front of the engine ares where the tops of the stringers were not glassed and rotting has started

Ok, Need opinions here:

As I posted the secondary stringers were really bad near the doubled up area at the rear of the engine compartment. Probably 90 % of the stringer was in good shape and hard to get out (like new wood)

Due to the fact of the failure mentioned, I am going to do the secondaries. How do people feel about cleaning up the main stringers where they were not encased, drill some holes perpindicular and inject CPES then brush the CEPS on the outside.... Then wrap in fibreglass lide the rebuild on the secondaries.

Has anyone seen the secondaries be real bad and the mains be OK ??

Thanks for your opinions and ideas.

Dennis

Dennis,

I'm doing my stringers one at a time. I started with the secondary on the port side. That was removed and the hull was ground clean. The new stringer is in place and has been filleted. As I mentioned, I used shims to hold it up off the hull. The reason for this is you don't want the wood to rest on the hull...you want a gap. I filled that gap with the thickened epoxy and that "glued" it to the hull. I've now removed the port side primary and I'm almost done grinding the hull for that one.

I'm really only a couple steps ahead of you.

I agree with Pete. Since you're already tearing up a lot of the boat, just clean it all out and put new in. Otherwise you're going to be doing this again soon.

Keep up the good work, you're coming along.

Dennis,
I do know Andy is using Doug fir.

I believe the shimming of his stringers is to level off the top surface to a finished height but he's using quite alot of filled epoxy! With careful scribing to to the hull shape, the amount of epoxy can be reduced. The important thing is to have the wood sit in a bed of epoxy taking up any minor gaps and sealing off the bottom side. A 1/16th to a 1/8" bed would be ideal.

Dennis,
I highly recommend the mini hand pumps. You will need to get them with the proper ratio for the resin/hardener you are using. Then, there is no guess work or inaccurate measuring. One full pump from each gives you the proper ratio.

If you are mixing large batches say for coating large areas, spread the resin out in a roller pan. If concentrated in a cup, the resin will "kick" prematurely. You'll end up with a very hot cup to the point where it will start smoking!! Use a plastic roller pan so the resin isn't concentrated in a small area building up the heat. Any resin still in it will break off when the pan is flexed the next day.

Dennis,

Yes, I'm using Doug Fir for everything I possibly can. Anything I don't use Doug Fir for will be Marine Grade Plywood.

I put about 3 sets of shims along the entire length, plus I used 1x2 across the top in a few spots to attach the stringer to the nearby stringer to hold it in place.

Pete is right, I used them the level the top and leave the gap at the bottom. My gap was more than it should be. I'm still learning the methods for scribing and cutting properly.

I got the pumps from US Composites. The thing I don't like about them compared to the MAS brand pumps is they are just a 1 ounce per pump set up, instead of being metered to the ratio you want. I'm using the medium hardener so it is 3 pumps of resin to 1 pump of hardener. I'm using cups right now because I'm mixing small batches. The cups I got from US Composites also, and they have the measuring marks on them, so it helps verify the mixture. As far as mixing in the filler, you just keep adding filler until the mixture is the thickness you want. Usually peanut butter or frosting consistency works well.

Here's some pictures that might help...

1988 2001 SN Stringer update:

Starboard secondary removed.

Rear


Front


I should have used previous advice and removed the engine & Tranny. I will do that today. Tired of climbing over and around it.

Question: Is it important to remove all of the resin/fillet buildup from the sides of where I removed the stringer? Or can I just clean it up and set the new stringer in the bed of resin filler and glass back in ?

Also, Between the stringers the factory sprayed or placed grey gelcoat (same as what is in the bilge) Does that need to be removed to the glass or can I just clean it and glass over it?

I will also want to clean up the bilge and repaint with bilgecoat.

Sounds good.

Thanks. I will wire wheel or clean to fibreglass inbetween the old stringers and in the bilge area.

Looks like you are coming along nicely. I've been grinding mine down completely until I'm to fresh glass and resin. Usually I can see the coremat material underneath. The only place I'm not doing that is in the bilge. In the bilge I'm making sure I grind away the bilgekote and the top layer of mat. Under that is woven roving so I am trying to leave as much of that behind as I can.

My grinding tools of choice are a 4" electric grinder along with a 24 grit resin sanding disk.

I'd agree on getting the engine out of there. I'd also try removing or covering as much other stuff as you can. That fiberglass dust gets on everything and coats it. Some items it can be difficult to remove. I found that out earlier this year when I did the shaft log on mine.

Dennis,
Start with small batches say a cup until you get a feel for the usage. When the fillers are added, the batch has the tendency to really grow!! When empty, you can just make more and even use the same mixing cup.

The 24 grit is a resin bonded disk. Same as what you would buy for metal.

What have you found to be good for grinding on the filit radius where the channel meets the hull? My 4-1/2" disc is not flexible enough to do it...

For finer/finish prep work the layered sandpaper flapper disks are nice. The big boxes have them.

I just looked at an old one; made by norton and called a flap disk.

Great, I was cutting out the stringer with the disk you are and was using some new type of sanding disk, don't remember the name ? I will take a picture of it. Cost like $8.00

I think the sandpaper will be a little more aggressive and give more control covering more area. I will give it a try.

Thanks for the mix blends of the resin... gives me somewhere to start