RickK's 170 rebuild

[Capt. Bob]

What's up with the surfboard?

I understand the sponge.

[RickK]

That's a filler for the front keel area. I glassed one side.

[RickK]

A little update but no pics.  I built a 16ft  (2x8ft) "form" to hold the stringers in their proper shape.  I then built 2 8ft tables and butted them together, set the forms in place and the covered them in visquene.  I then dropped the first stringer on top.
I layed 2 full layers of cloth on them - 1x1808 and 1x1708 wet on wet.  So now there is 2 full layers and 2 sectioned layers.  The 6ft sections are glassed together with 3 layers of cloth and mat at each seam.  Should be stout enough.
I ordered the epoxy today for laying a layer of 1708 across the inside of the full hull.  Hope to have that done this coming weekend depending on the temps. Then I'll start fitting the stringers, notching the tank in and planning the seat for the tank and then the bulkheads.
Nice to be back in town.

[gman 82 aquasport]

Sounds like it's coming along nicely..How long are the stringers once finished before you cut to shape to install?

[RickK]

14'6.  I'll need 13'6 - leaves room for the cut twice measure once or is it....

[gman 82 aquasport]

Way to think ahead

[seabob4]

14'6.  I'll need 13'6 - leaves room for the cut twice measure once or is it....

Yeah, that's it!  

[RickK]

I ordered in some epoxy to give the bare hull some strength and started working on laying half of it up.
It took about half a day to do any last minute grinding and then cut all the pieces of cloth in advance.
Since 1708 sucks at going over even the smoothest bends without air pockets, my plan was a to mix some thickened epoxy aka "putty" (cabosil and chopped strand) and pull a nice wide gentle fillet in along the chine and fill some of the sharp area of the keel.  I also wanted to fill the strakes to allow for a smooth transition across the bottom of the hull for the new glass. I also wanted to lay a strip of 6" along the chine and a 8" plus 12" in the keel from transom to top of bow.
This was the first time I worked with epoxy so I wasn't real sure how much working time I had using slow hardener - temp was about 70ish.
We mixed up what we though was enough putty and got through the chine, the keel area and about half of the strake.  Twitching because of the working time unknown we quickly mixed up another 2 qt mix - thicker this time.  Finished filling the strakes and filled some of the inconsistencies along the hull bottom with what was left.  The putty was trying to slide out of the strake so for the next 30 minutes I fussed with that and I could tell that the resin was starting to firm up (or so i thought anyway).
So we started the mixing process of the 2:1 resin - would need about 3x3qt batches (2oz per sqft). We started laying in the keel first - went in ok and my thought process was to lay that first and then everything would lay over that and tie it all together. The intention was good but boy was that a mistake in planning. Made it an ice rink in the hull. Made laying everything else dangerous - for the next guy - lay the keel last.  I don't think it matters whether the layers are on top or bottom, it's the layers that count.  I was lamming the chine and stepped in the wrong place and wham,  I was on my back with road rash on an arm in an instant - WOW.
What was amazing to me was the working time of the slow hardener in cooler temps.  We started at 3:37p and finished at 6:30p - I used the same roller sleeve the whole time!  I was also surprised at how the wet out was different with the epoxy vs the poly.  Poly is much easier.  Plan a little more than 2oz/sqft on the epoxy.
Obviously I was pre-occupied so I only have "after" pics. The sun was starting to go down so the pics aren't that good. 3 layers in the chine and 3 in the keel so far.


The specs of the hardener said if using it in 70 or under "extended" curing times were possible - 18 hours later it was still tacky and even wet in some places.  The slow hardener is for 80+ temps and then you get an hour of working time.  This stuff should be hard by next weekend since we're supposed to be in the 40s and 50s for the lows.  To help heat it up we dropped the tarp, which was finally starting to get torn, down and clamped it to the hull - should raise the temps nicely. Maybe the slow cure is a good thing. Next weekend I will finish the hull layer.

[slvrlng]

Thats one thing about epoxy, you can just keep laying more on and more on. It does wet out completely different than poly. Sometimes I wonder if you can ever thicken it too much. If you didn't have to work tomorrow you could just go and lam more right on what you did today. Once cured it will be so much stronger you will never have to worry about it again. You should get some medium hardener to make your fillets with so once you get them right you can go ahead and lam right over them without worrying about them continuing to flow. It is looking really nice!!!!!

[slvrlng]

Couple of more things!  Don't let that tarp fall down onto the tacky or still wet spots! It will stick and you might be able to grind it off next week!!!!   I always take a small amount of neat epoxy and put it in a mixing cup just to check if it is curing correctly or not. That way you don't have to climb in to check it so often.

[gman 82 aquasport]

Rick, when I laid my hull and floor last winter I used medium hardner while the temps were between 45 and 60 degrees..it would stay wet for about 1-3 hours depending on how much light I had on it.( multiple haligen work lights).
It would be hard by the next morning, I never left the lights on overnight..I tried to do a wet on wet lay-up on my floor and like you I went skating  and had to take the top layer off and wait till it dried overnight then sand, wipe with acetone then start the next layer..1708 does soak up some product   If your not going to be able to do anything till next weekend you should be fine..It will probably be hard by Monday evening keep us posted

[RickK]

Couple of more things!  Don't let that tarp fall down onto the tacky or still wet spots! It will stick and you might be able to grind it off next week!!!!   I always take a small amount of neat epoxy and put it in a mixing cup just to check if it is curing correctly or not. That way you don't have to climb in to check it so often.

I can just reach over the transom and side to check the tackiness.  I'm not climbing into the boat, I don't want to move the hull sides until it's totally cured - trying to stiffen that up. We're not expecting any rain so the tarp should be fine clamped as it is.

The next half will be much easier since the keel area is done. I can work it like it's supposed to be done without that "feeling" of sliding and falling again. I was using a roller on an extension pole too - still too dangerous.  Almost wish I had a scaffold above the boat.

I think I will make up the putty extra thick and lay it in an hour before I start the cloth lamming. Supposed to be 60s for lows and highs in the upper 70s by this weekend.  

It will be nice to get a strong substrate to start building on top of. Once I can get the stringers cut to fit and then mark out the fuel tank notches I'll feel like I'm getting somewhere.

[dirtwheelsfl]

Looking clean  

[RickK]

Lam was rock hard tonight.  

[seabob4]

Just a reminder, adhesive (epoxy or poly) will cure at a faster rate in a cup than wetted out on glass over a large area...Lewis!