Sanger stringer repair

Anybody out there with experience repairing stringer rot in a Sanger 20 DLX? I'm looking for some guidance on how to get to the front end of the stringer. From what I can see, it looks like there is a floor material transition from wood to ? almost where the front bow seats start. I can cut out the wood floor under the port side console, but it looks like the wood floor ends before I can get to the end of the stringer. As far forward as I have cut into the stringer, it is a spongy mess, so I'm assuming the whole thing needs to be replaced. Anybody with direct experience on the subject....?

I realize there are many who believe this cannot / does not happen to Sangers, and if it does there is a lifetime warranty. I used to be one of those people too....now?....well, not so much. When I first discovered this issue (loose ski pylon, engine mount settling), I was told (by Sanger) that warranty only applies to the original owner and was quickly dismissed. We bought the boat when it was 4 years old, and used it for many, many trouble free years. I started to tear into the boat some time ago, but now I'm on a mission to finish it. I'm passed most of my bitterness with Sanger, and now just looking to get my boat back on the water. Any help would be appreciated.

You are not gonna like this....

You will have to split the cap.

You're right....I don't like that. Is that even possible as a DIY? Splitting seems like a possible, but then it would have to be removed / lifted in order to get to the stringer....I think. That sounds like time to get a new boat???

Do you know if it would be possible to dig through the wood floor as far as possible, hollow out the remaining length of stringer hat section under the cap, and then fill that glassed section with "something" that bonds to a replacement wood stringer that runs the remaining 7/8's of the boat?

Maybe if you can get to an area over the fwd sections you could do a drill and fill right through the deck. I dunno...

For splitting the cap, look to the Supra forums as they are the largest group of older open-bow boats to undergo stringer replacement. Many of their members have done it.
What, you dont have an overhead crane or a track hoe handy? No issue, get it ready and call a wrecker to pick it up.
Look to the CCF site for the best how-tos on actually doing the glass work.

dang...my wrecker is in the shop.....

thanks for the input. I'll check out the Supra forums. What is the "CCF" site?

Correct Craft Fan

Bunch of guys with old ski boats with tons of knowledge on exactly what you are trying to do.

http://correctcraftfan.com/forum/default.asp

Correct Craft Fan

Bunch of guys with old ski boats with tons of knowledge on exactly what you are trying to do.

http://correctcraftfan.com/forum/default.asp

Would it be possible to shape a new stringer and slide it up beside the existing? Bond it into place next to the existing?

Though it is not sanger specific lookup friscoboater jay on YouTube. He has documented two rebuilds of rotted stringers, one with videos of every step.

the real problem with jerry rigging a fix is how much time and money do you want to put into a questionable repair job? or do you want to do it once and do it right?

you'll get to spend some quality time with a grinder before the job is done. fiberglass dust is nasty stuff. move the topcap out of the way and you get great access. try to leave it in place and you'll not only have to work around it you'll also have to wrap it very well and still have to clean it up afterward. dust gets everywhere.

there are lots of ways to pull the topcap. they aren't even very heavy they're just big. the bow/windshield area is where most of the weight is. the rear is floppy and needs support but doesn't weight much. i used pulleys mounted on 4x4 posts and then pulled the trailer out from underneath once the cap was lifted off. when the stringer job was done, moved the trailer back in place and lowered the cap. heavy equip is definitely quicker and easier.

it seems daunting before you get started but none of it was very complicated. 80's inboards weren't very precise engineering feats. the trickiest part is mixing and working with fiberglass but that doesn't take long to figure out.

Id suggest calling Gary @ Classic Craft in Rancho Cordova. He is qualified and can do it rather quickly. He does great work and most of the hard part is done for him to get to the problem areas. that boat is identical to mine. I hope it never needs this....

thanks all for the comments....all good info. Sistering a stringer next to the existing...not sure. I need the good stringer in the same location for the engine mount. The old stringer is completely trashed...mush. So it's got to come out.

Rather than separating the cap, I was thinking.... I think / hope I can get far enough along the stringer through the floor to get the whole glass hat section cleaned out to the end of the stringer....the last small length being under the cap. Set a new stringer in the boat with the front end protruding just into the fiberglass hat section under the cap. Then drill a hole through the cap into the top of the glass section and fill the front of the stringer bay with a cast material. I know not the best, but it is a small section of the stringer in an area with a lot of other structure. I talked to another boat guy who thought that would work just fine. He said not bad with the cast material being in just the very front. It's time for me to become one with my grinder......

TIPs: pull a section of your least favorite pantyhose over the grinder vents to keep the brushes and bearings a little cleaner. Blow it out with air after using.

Tyvek suits are like $8 and worth every penny X100. Tape the cuffs.

A square box fan with a cheep AC filter taped to it can really help control dust.

Use your neighbors trash cans after they put them out if not full. I put 1800 feet of old laminate flooring out in one night..took the whole neighborhood... the trash guy was like WTF? My neighbors are used to me now.

Get a garage fridge so you dont track up the house every 10 minutes for beer.

If you can get the boat off the trailer and get it leveled it will pay large dividends when setting the new grid. Level the boat now so you can level the grid later.

Make your templates now while you still have a model.

Glad its you and not me. Two full stringer jobs is enough, never again.

Put in a new steering cable.

Pull the cap, anything else will just waste a lot of time and effort trying to work within those constraints. Check correctcraftfan.com/forum and supraboats.com/bbs, many stringers jobs detailed on those sites. Read through a few and be sure you have the space, time, and money to take it on.

From all the stringer threads I've seen on various makes of boats it should be easy for a first timer to do a at least a better job than any of the manufacturers did. So many of these boats have no drainage, exposed wood, and of course the foam is what holds water and starts the rot. I'd recommend no foam, if you use any flotation keep it under the gunnels and bow where it'll stay dry and make sure you have good drainage to the bilge.

Thanks to all for the pointers to the other sites....tons of info out there. Benny in Tracy has also been a huge source of info and a great help. The proverbial sleeves are rolled up (not really because of itch factor) and project is well under way. Stringer almost completely out (Cap still on ). Not sure why, but I was expecting a little more "science" under the hood. This boat construction is pretty basic. I've discovered lots of areas for improvement when I put it back together. Progress and pics to follow.

I can provide some insight as I just finished doing my 85' Supra Comp.

We were lucky in that the main strings were still in good condition compared to the other "stringers" which were more like soggy news papers and didn't have to rip the cap off as we could access the other stringers. Obviously back in the 80's these boats were all built on Friday shifts. The big goal you want to achieve is getting the boat off the trailer or at least supporting it with blocks so that you can get the hull back to its natural shape. We achieved this on ours by lifting it off the trailer and using wood blocks to support each corner of the transom and bow…we were surprised how much shape came back (almost 1-1/2" on port and starboard).

We ended up using 3/4" plywood laminated together to give additional rigidity. It was overkill but if there were a couple soft spots in the main stringers this would help distribute the load as we also created a new engine cradle and tied the exterior stringers to the mains. I highly suggest coating every piece of wood in resin, we put 3 coats on everything as this is the one and only time we want to do it. We also added foam back in as I feel safer knowing its there (it is the proper 2 part closed cell foam, and we also coated the top/sides (where we could reach) with resin to further protect it if we had to trim some small areas.

For reference (as I forgot to grab pictures), we used 1408 weave on the bottom of the stringers where they meet the hull to give added strength and a thin layer of CSM over the top to add extra protection. For the most part the reason they did that in the factory is because they used unprotected wood.

What we started with:




New engine and cradle:


Stringers with the bedding mixture and epoxy sealed:


Foam Installed:



We also replaced the blocks of wood used on the transom for the swim platform and fiberglassed it in, along with aluminum plates which sandwich against the fiberglass and wood for extra load spread:


Final Product: