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Sanding Queries

Posted: Sun Jul 20, 2014 11:06 pm
by mdweber
Hello Folks,

I got my squirt flipped over today, and it looks like I will have a few more days of sanding before I can start framing the deck. There are a few tight spots where I need to remove dried epoxy, but I'm not sure how to access these areas. I'm hoping you guys could help.

Spot 1: The small space between the outermost batten, transom, and the chine knee. epoxy was forced into this area when the bottom planking was applied. The space is about the width of a finger.
IMAG1019.jpg
Spot 2: The open space between the frame member and the side planking. I did not intend to leave such a large gap, although Building with Plywood actually recommends doing this. I plan to either leave the gap and encapsulate the wood on either side, or fill in the gap with epoxy. Either way, I need to sand both the plywood and the frame member.
IMAG1022.jpg
Looking forward to your ideas!
Mike

Re: Sanding Queries

Posted: Mon Jul 21, 2014 6:35 am
by vupilot
I cant see what you are referencing in the first pic. The white epoxy looks clean and nice. I would leave it. Depending how your planned deck is going to be like you may hardly see much outside of the actual cockpit area. Yes youll want to get some encapsulation in all those nooks and crannies like that one shown though.
Encapsulation epoxy is fine on the planking and frame but dont fill the gap. Like you said the instructions say not to. If the gap is a bother maybe caulk it instead?

Re: Sanding Queries

Posted: Mon Jul 21, 2014 11:49 am
by mdweber
Hmmm. Interesting suggestion to use caulk. What would the issues be with filling the void between the the frame and the side planking with epoxy?

Re: Sanding Queries

Posted: Mon Jul 21, 2014 12:35 pm
by Bill Edmundson
Mike

The designs that I have built called for the skin to be glued, not screwed, to the frames. A screw here and there to pull the skin down is ok. But, not a line of screws. I'm not going against the book. But, there seems to be different opinions.

Bill

Re: Sanding Queries

Posted: Mon Jul 21, 2014 1:09 pm
by mdweber
Bill, that was my interpretation as well. From the literature, it seems as though the problem with screwing the planking to the frames (and not just the longitudinal members) is that it weakens the plywood, causing it to fold instead of bend. I'm not thinking about sinking screws in this area, but only filling the gap. I was thinking epoxy to fill the gap, but I'm interest in hearing the caulk reasoning. I have never worked with caulk before, but it might be good experience before I have to use a whole mess of it for the deck (....or I might just use thickened epoxy for the deck seams, but that will be another topic for another day!).

In either case, what is the best way to rough up these hard-to-access areas in preparation for epoxy, encapsulation, or caulk? Maybe a flexible board with 80 grit stapled to it?

Also, I came up with a way to remove the thickened epoxy from the tight spaces like in the first picture. I have been using an oscillator tool with a 1-1/4" blade to carefully section away the epoxy. A bit dangerous, because a slip could slice a hole in the boat. Perhaps that would be good because then I wouldn't have to debate where to put my through hull transducer!

Re: Sanding Queries

Posted: Mon Jul 21, 2014 1:20 pm
by gdcarpenter
Multi tools are, we'll, multi tools!

I'm of the school of epoxying but not screwing hull ply to frames and did so on my ZIP. To epoxy the frame side gap I'd fold some 80 grit and roughen it up a bit, no need to be too thorough, hull is already structurally strong. For tidiness I might cut 2 pieces of scrap to match the curvature of the hull, wrap them with wax paper, and clamp onto opposing sides of the frame, leaving a filler hole at the top, then syringe in some slightly thickened epoxy.

Re: Sanding Queries

Posted: Mon Jul 21, 2014 2:58 pm
by Bill Edmundson
I've been using PU construction/adhesive caulk as a filler for the gaps. I know, blastomy (sp). But, you're just filling gaps and keeping water out.

Bill

Re: Sanding Queries

Posted: Mon Jul 21, 2014 3:58 pm
by vupilot
Yep, I was mis-remembering. You can epoxy them to the frame just recommends not to screw to the frame. Even us young-ins cant remember it all.

Re: Sanding Queries

Posted: Mon Jul 21, 2014 6:14 pm
by mdweber
Chris says its okay, then its okay. More epoxy sounds good to me.

Reading through the plans again last night, I saw that the build calls for only one quart of epoxy.....LOLOLOLOLOLOLOL. Maybe a quarter of a barrel.

Re: Sanding Queries

Posted: Thu Jan 01, 2015 8:12 am
by chugalug
:D How about using Log Cabin caulking-(log builder)It's kind of spendy in small tubes,but you can also get it in 5gallon pails too. :D

Re: Sanding Queries

Posted: Fri Jan 02, 2015 8:39 am
by Soloboat
I had many similar gaps. I filled with fiberglass insulation mixed with epoxy thickened with wood flour that combination worked best for me.

Re: Sanding Queries

Posted: Sat Jan 03, 2015 5:47 am
by cusoak
In reguards to filling that gap between the frame and inside plywood, West system sell a caulk tube with a two part epoxy in it with a mixing nozzle. It is to be used on wood boats where some flexability is necessary.
It is mixed as it comes out of the end of the nozzle.
I have used it to put down the covering boards and deck boards on my Zip znc 1966 Century Resorter. These are areas that need to flex some what when running in the water.
I would back up one side of the frame with a piece of wood or carboard faced with wax paper. Clamp it to the frame. Make one for the other side too. Force the epoxy into the gap, when full place the other piece on to the frame and clamp it. Clean off any excess epoxy right away. Wait till it drys the take back up pieces off and you will have a niceely filled gap.
That is some what flexable.
West System Six !0

Jeff