Time for a small celebration.....

rick1954 · Post by **rick1954** » Fri Apr 04, 2008 10:43 am

Mac32,
I assume you cut the tops off the stringers and removed the rotten material only or did you remove all the stringer? How did you make the templets to fill the area to be repaired?, Once the material was replaced, did you fill in the area with resin then rap over the top with new fiberglass? What material did you use for the stringer? Okey only one more question, what mesh size did you use for the fiberglass?

I want to replace some section of stringer that has some small amount of rot in it, just in front of the motor at the bulkhead to the cabin. The front and rear stringers are joined together at a 45deg at that bulkhead and it seams to be a little punky, everything else looks very good. I will be removing the motor this fall to rebuild it, that will make a good time to repair any stringer problem that may be occurring.

Mac32 · Post by **Mac32** » Fri Apr 04, 2008 12:33 pm

Rick
I will try to abreiviate and still answer all of your questions. But click the pictures in the beginning of this post photo album, most of these pictures are in there.

I did cut the tops off of all the stringers and vaccum out all the rotted sawdust that was a solid stringer. I laminated using West system epoxy (4) pcs of marine plywood (2) 1/2" and (2) 3/4" to make a 2-1/2 wide stringer. Then I bed it in with thickened epoxy and wrapped the tops with 17oz and 24oz heavy roving fiberglass (buy online for $$ savings)

PRO
Helped support hull from sagging
Great template for dropping in new stringer (used carboard for shape)
Wasnt so scary to do it all at once

CON
Took way more epoxy and filler to fill all the voids left by the factory bedding
Tedious shaping the bottom of the stringer to fit factory imperfections.
Would have been 2x fast bedding new stringers to a bare hull and probably still use the same amount of epoxy.

Also my stringer overlaps completly between front to back go to my album and look at the full stringer port, you can barley see it but its there. And where I did splice the stringer I tried to get a 2 to 1 ratio on the overlap (1" rise for every 2" back)

Good luck, now that I am done it wasnt so bad, just time consuming. also remember to stay paitent and keep the area clean, especially when using the epoxy or resin.

yorklyn · Post by **yorklyn** » Fri Apr 04, 2008 2:39 pm

Mac,
I hope you don't mind a few more questions. I just completly cut out the main starboard stringer on my 10 meter. I took it all the way down to the hull because It seemed like it would be quicker than diging the wood out. I just bought the big 4.3 gal west system kit and 24 ounce biaxle roving with mat stitched to it. I'm using 2 layers of 3/4 plywood to get the 1-1/2 that was there.

the cloth I purchased is 25yds X 50 inches per roll. I was origionally going to try to use a single piece of cloth to cover the entire 15'2" stringer. I made a stringer mock-up about 20 inches long and bedded it to a piece of plywood. I attempted to glass it last night and realized that there is no way I can do it with a 15 foot piece. Any suggestions on how big a section to attempt at one time? My stringers are 19 inches high so a 50 inch cloth will give me around 5 inches of tabing on the hull on each side with no cuts.
I am going to attempt to apply 2 layers of cloth to the stringer in one day so I get a chemical bond between layers. I was thinking of working with around 5 1/2 feet of cloth at a time.

BTW How much epoxy did you go through? I just got a port supply account through west marine and was able to purchase my stuff wholesale, Talk about luck!!
Thanks

Mac32 · Post by **Mac32** » Fri Apr 04, 2008 3:56 pm

Todd,
I ended up working in about 4-5 foot sections depending on where they landed on the stringer, and ended up doing 3 layers (probably way too much) in order to overlap and stagger the sections. This was quite a bit of epoxy to mix at once, so the biggest trick I learned was to use the slow set hardner and mix it in batches of 15-20 pumps of epoxy. The other HUGE help was when I went to the local bulk resturaunt supply store (Gordon food service here in MI) and got a bag (50) of the plastic Deli cups $3 (for potato salad and such), bag of 100 latex gloves $6 and then went to the craft store and purchased 300 large popsicle sticks for mixing $3 (they also have a great radius end for flair on the filler. So with every batch I throw the gloves and mixing sticks out and set the container aside. Then the next day I could flex the cup and crack out the old epoxy and re-use the cup.
I tried to use the flexible mixing sticks but didnt always time it right and it was way too time consuming to bend and chip off the old epoxy.

Regarding Epoxy usage I used (6) or seven gallons of epoxy for the whole job and wished I had purchased the Big bulk one like you did.

Just as a side note though, I found out West marine will price match with online sources like defender so I started getting the gallon cans of resin for as low as $68 from westmarine instead of the regular $98. I am actually back to liking west marine again for the name brand stuff.

Hope this helps, Good luck , be sure to post pictures of progress....

Oh one last note, on a big job like this I noticed that I could never time everything to get the layers to be a green chemical bond, so in those instances West system recomends scuffing the surface (I used 60 grit) before the next layup.

yorklyn · Post by **yorklyn** » Sat Apr 05, 2008 11:43 am

Thanks Mac,
I appreciate the help. At least it sounds like what I'm planning on doing should work. I figured the slow hardner was the way to go. This stuff is too expensive to screw it up so I'm planning on taking my time. From your pictures it looked like you did a great job, Good Work!!! I will hopefully have some progress pictures posted in the near future but I have quite a way to go before I get to where your at.

Thanks Again!

rick1954 · Post by **rick1954** » Mon Apr 07, 2008 7:06 am

Thank you Mac,
your information is going to be a great help.