1973 196 rebuild question

[Duffy1470]

Also, picked up two sheets 3/4 in Coosa, 5 gal of poly resin, mek, bubble buster roller, roll of Matt, and got a roll of something heavier than 1708.  The heavier stuff was a "good deal". We'll see. At any rate, going to patch holes in outer skin of transom first.  Question, I know it's 11ccs of me for a quart of poly resin at 70 degrees Fahrenheit, less if hotter.  How much less, say at 75, 80, 85 degrees. It's getting hot here 8n tn. Thanks.

[RickK]

Roger that on the 16-17 foot mold.  I think the answer must be really obvious and you are not wanting to insult my intelligence or lack thereof, but why rebuild stringers from the Inside. Are inside out rebuilds stronger or something. The answer could be my proposal, if executed, will look stupid which is legit.  Just curious. If I need to stop asking, I can do that too.  Thank you for all the info, truly a great resource.

To me, rebuilding them from the inside out is too labor intensive and if the stringers have breaks in them, even worse. Mine had tears and previous rework (by me) so I decided to tear everything out, re-enforce and build new. My boat is like a tank now.

As for the MEK mix, try dividing the resin into small/smaller batches and adjust the MEK by the same divide. You don't want to learn with a quart. If its cooler reduce the MEK by a few drops and see how quick it kicks off. Also, keep the lid tight on the poly, it starts hardening the day it is made. You want to buy in small quantities so it's always kinda fresh.

[Duffy1470]

Thank you Rickk. I get it now. I can be a little dense. 

[Duffy1470]

Bunch more to go. Ran out of gloves. Get gloves.

[umecheme]

Find 'em cheap, buy a case. And find a good source for respirator cartridges.

[Duffy1470]

Sage advice umecheme.  30 years ago when I did my last boat rebuild (stringers and deck on what we think was an 18 almond that looked like a wellcraft v-step), we would patch holes by tearing pieces of mat instead of cutting.  I did both here. Is one way better than the other or is it personal preference?  Thanks for everyone's input. Very cool.

[RickK]

I've done it both way with CSM. When I tore it I was repairing something, like my 170 had been beached so many times that the keel was worn through in one spot but the previous owner had painted it over and I didn't see the damage. When I did find it (because the boat almost sunk), I tore the 1.5oz csm and tucked it in and around the gouge that was now present because I ground it deep. After a few layers I could start adding cut pieces of 3oz csm and went back and forth between torn and cut until it was filled.
Oh, and use your air compressor to blow out the motor on your fan often. I borrowed a fan from my buddy and after a while the motor was getting hot and started to not turn on. I blew it out and all kinds of stuff (he never blew it out since he bought it) came out. I did this from several different angles until it was clean and it started back up and spun much freer that when I received it.

[Mfarmer1020]

Hey guys, sorry to come in with no info and just questions but im in the same boat here (literally lol). As i go through all of these rebuilds and see all these photos im curious to what i have going on with mine. I see alot of pyramid stringers and that i do not have. Have attached photo (i think) to give you a look. Wondering if this is factory or someones handy work in here. The two center ones have 2x4's attached from a tank replacement before i purchased so i know thats some handy work but mine are completely different. Wondering if this is factory or if i need to start from scratch from the bottom up! Thanks in advance for any info!!

[RickK]

I would say that it's someone's handy work. Is the wood dry? Take an awl and probe the wood, if its mushy, it's toast. If it's still hard then it may be fine.  Wood in the bilge is not a bad thing as long as its sealed very well and water doesn't get into the bilge.
Start a new topic here - https://classicaquasport.com/smf/index.php?board=30.0 - and post your questions.

[Mfarmer1020]

Wood is in bad shape but was wondering more if the design of the stringer is good or not as i see mainly pyramid ones in all boats on here yours included rickk!

[RickK]

Aquasport was the first to have fiberglass stringers. They made them trapezoidal in shape for strength and filled them with foam to help support the structure of them. That being said, all other manufacturers at the time didn't have any choice but to make them out of wood, and they lasted a long time. a friend was buying a grady white cabin boat and he asked me to check it out. I opened the bilge and there was wooden stringers - I stuck a screwdriver into the wood and it was very soft. I told to get his deposit back.
So, you have a decision to make. If you decide to rip the wood out, it's not hard to make your own trapezoidal stringers from homemade molds.

[Duffy1470]

Looking forward to your response as I am struggling with same question.

[dbiscayne]

Theres some science to the stringer design and how it works with the adjacent hull 'flat' areas. They need to work together and have similar stiffness properties. A stringer thats overly stiff next to a hull panel that flexes a lot, ie small boat, can cause problems. I've seen two separate cases of a hull tear along a stringer because of exaggerated differences in stiffness of the two. I'm no expert at this, but from what I've read and seen its good practice to not have a wood stringer laying directly on the hull, instead they should be separated with small spacers, +/- 1/8" then a proper fiberglass fillet connecting them. With all that said, as long as you don't beat the crap out of the hull it might be OK without that gap.
Seacraft also used the fiberglass box stringer and they've got a great reputation.

[Duffy1470]

Good info dbiscayne.  Thank you. Here are a few more pics of hole patching and bow eye prep.

[Duffy1470]

Something wrong with my machine or the gallery. Will post pics later