Ohhh- poxy

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ZippyChippy
Posts: 2
Joined: Tue Feb 27, 2018 8:52 pm
Location: Belleville, Ontario

Ohhh- poxy

Post by ZippyChippy » Sat Mar 03, 2018 12:03 pm

Long time listener first time caller to the builders forum as I slowly complete a 15ft "Kite" solo canoe for my first build. This group has been a great help over the embarrassingly long time it has taken me to get to the fiber glass and epoxy stage - so thanks to all you expert boat builders out there, your insights are much appreciated.

Now my plea for help...

Fiber glassed the outside last weekend, sealer coat then 3 coats of epoxy with a roller, squeegee, foam brush to "tip off". Problem is (besides some runs) there are +/-50 visually and tactile ridges / bumps in the finish. all essentially running parallel - my theory is that these were caused by:

1) creases in the FG caused by me unrolling and then rerolling the FG before putting it on the boat (to test fit and cut it);

2) then likely storing the FG roll vertically after a overly loose re rolling that introduced creases / sagging of the stored FG;

3) Insufficiently aggressive squeegee pressure to flatten any ridges out (lessons learnt)

Pictures:
Image

Image

It seemed like everything was lying flat with no ridges on boat before the epoxy but I guess not. I have started with the scraper to knock down the ridges , but can't get to flat / fair before hitting the FG - leaving the tactile / visual ridges.

My plan is a light sanding over the whole boat for a mechanical bond then another epoxy coat rolled on while attempting to build up / have some extra epoxy depth in the areas besides the ridges by running the squeegee parallel to the ridges so that the epoxy is aggressively scraped from the top of a ridge for little thickness build up but more remains in the "valley" below it in order to feather out the difference as much as possible.

Good plan? Any alternatives I should consider? I assume I should not be cutting all the way into the glass to get to fair first but maybe that is an assumption I shouldn't make.

Insights / advice much appreciated, thanks in advance.

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Jim Dodd
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Joined: Wed Feb 08, 2006 11:08 pm
Location: Iowa

Re: Ohhh- poxy

Post by Jim Dodd » Sat Mar 03, 2018 5:31 pm

Welcome Zippy !

A few questions ! What epoxy did you use ? And did you get the cloth from the same supplier as the resin ?
I'm puzzled by the ridges !


I eliminate runs, by applying Fill coats about 1-2 hours apart. Depending how the epoxy is curing.
Wanting my the previous coat Still tacky when I apply the next coat ! This Tackiness Holds the resin, from running !.

You stated, you applied a Seal coat ?

OK. I apply a Seal coat, and let it cure to a tack free finish.
At this time, I go over the hull, with a gloved hand, to feel for any irregularities and SCRAPE, them off. These irregularities, are usually dust particles. They will prevent the cloth from laying tight against the hull !
Lay out my cloth for the very first time. Trim it to about 2" over hang. Tug on the ends, and this takes out any wrinkles.
I'm ready to wet out the cloth.
Wet out the cloth, and let it cure to a tack free state. There is enough texture to hold your first FILL coat. Usually, Two more FILL coats, and I'm done !
Often times, it's the middle of the night before I put that last coat on !

Jim
Keep your paddle wet and your seat dry!

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Cruiser
Posts: 610
Joined: Sat Apr 27, 2013 10:21 am
Location: Bowmanville, Ontario

Re: Ohhh- poxy

Post by Cruiser » Sat Mar 03, 2018 10:25 pm

Zippy,

I have seen the ridges you have running from bow to stern and they are from deformation (like a soft crease) in the cloth, likely as you hypothesize from rolling and rerolling the cloth ... tip here, do not play with the cloth ... leave it until you are ready to do the job (that's for next time). Take a good carbide scraper and level those, into the cloth if necessary, more epoxy will not help fix those. If you have to cut through the cloth to get it level ... if you cut all the cloth in an area, you may need to add bias cut strip and feather the edges. I have never found any other way to deal with those type of creases.

I also note that you have some "lumps" running vertically ... keel to sheer and I believe those are from glue getting under the glass, likely due to the squeegee process not getting the glass pressed against the wood well enough. Those will need leveling as well, using pretty much the same idea as above.

A compromise would be to level as far as you can with out cutting through all of the cloth (the compromise is that it may not be pretty, your call), finish the rough sanding over the entire hull, then do a thin recoat with epoxy to seal everything. Finally do the finish sanding (a light sand with 120-150, I use 150) to take the shine off.

Any way you look at it, you have a lot scraping ahead of you, hope you have a good, sharp carbide tool .... if not go and get one, they aren't too expensive.

My $0.0s worth


Brian

ZippyChippy
Posts: 2
Joined: Tue Feb 27, 2018 8:52 pm
Location: Belleville, Ontario

Re: Ohhh- poxy

Post by ZippyChippy » Sun Mar 04, 2018 2:06 pm

Thanks Brian and Jim. The scraper and I are already becoming intimately familiar with each other.

I used West System 105/ 207 with everything nice and warmed up. FG was from Noah's in Toronto. Pretty sure its not a materials issue (the guy at Noah's handled things quite carefully) but was rather a materials handling issue on my part.

I have done some testing on a scrap piece to see how things will look if I go material down to / in the FG and then also past the FG to the bare wood and recoat with epoxy/ Preliminary results are that it looks like you can't get the white FG weave pattern to disappear with the more you cut into it the worse it will look (I will try to post pictures). Consequently I am a gun shy to materially cut into the FG to get to level right now...

I have also tested another alternative which is a lighter scrapping of the high spots / ridges until I just hit the FG/ Then I apply some epoxy to try and feather out the ridge by squeegeeing perpendicular to the ridge to have a minimal amount on that high spot with hopefully some more build up beside it. Pictures of a few test areas which are still drying:

Image
Image
Image

I will be interested to see if this will work (probably not even an option on the vertical sides because of epoxy running - but maybe for the top anyways).

In any event there will be another epoxy coat to go on, should be interesting.

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Cruiser
Posts: 610
Joined: Sat Apr 27, 2013 10:21 am
Location: Bowmanville, Ontario

Re: Ohhh- poxy

Post by Cruiser » Sun Mar 04, 2018 4:15 pm

Looks like you have it in hand .... I am not that far away if you need a hand at some point.


Brian

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