First glass - looking for tips/advice

Going to be a big day in the old boat factory tomorrow.  Time to run fillets and tape on the hull seams of our Shearwater Sport and, if time and confidence permits, glass the cockpit area.  The manual advises against letting epoxy pool in the bottom of the boat when wetting the cockpit fiberglass cloth.  My question is how do you prevent it?  The side panels are essentially vertical.  How to you stop the epoxy from running back down to the center of the bottom panels?  I have the yellow plastic squeegies.  Do you just keep pushing the glue up the sides until it thickens sufficiently that it stays there?  Is there a point of dimiinishing or negative returns from doing that?

Thanks for any advice.




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RE: First glass - looking for tips/advice

   Hey Jim, can't answer your question since i am about to start building my NE Dory, which will be my first build,  but I saw that your profile name is Florida Jim.  What part of Florida do you live?  I am in the Stuart area.  Might be interesting to follow each others progress.


RE: First glass - looking for tips/advice


Just be careful how much epoxy you put onto the glass in the first place. If the world was perfect, we'd be able to put on exactly the amount it takes to wet out the epoxy and bond to the wood. Then, there wouldn't be any left to pool on the bottom.

The world not being perfect, we just have to be careful not to put too much on the glass, then deal with the extra. Ways to deal are:

1. Start with the sides, not the bottom. That way anything that drips down gets absorbed by the dry glass.

2. If you do get a pool, and the glass and wood have already soaked up as much as they can, soak it up with paper towels.

3. This one's a bit messy and needs some skill, but it comes the closest to perfection. First, precoat the wood with epoxy. Use a squeegee to make sure that there's no extra anywhere. Then, on a workbench covered with a piece of polyethylene dropcloth, wet out the glass. Since it's flat, you won't be fighting gravity and you can easily control pools . When the glass is completely wet out, roll it up the long way and move it to the boat. Unroll it and adjust it into position. Use the edge of your gloved hand as a squeegee to press it onto the wood and to squeeze extra epoxy, if any, onto the dry wood.

#3 should be done as a single step with no delays, so have everything set up and ready to go before coating the inside of the boat. A helper may be useful. It will potentially be very messy, so long sleeves, hats, etc. are in order. If it seems like too much trouble, then by all means skip it and go with one of the other 2 methods.

Good luck,



RE: First glass - looking for tips/advice

I think Laslo mixed up tape and glass (cloth) advice? -for interior glass, you can't start on the sides; you always need to start somewhere near the middle and work toward the edges, or start at one end and work toward the other end. A plan that causes a dry "island" of cloth will not work out well, espcially on the interior where it is inherently difficut to keep the cloth in contact along the interior corners. It's an ironic truth that the first glass cloth that goes into these boats will be the most difficult to install. Everything you do is trying to cause wrinles to form or bridges at the corners. On the outside cloth, everything you do causes the sloth to be pulled tighter and conform to the shape.

Unless you have a long day availibale, plan to do your taping (fore and aft compartments?) all at once, and then the glassing for the cockpit on a 2nd day.

For the cockpit glass (assuming you don't have anachronistic instructions calling for tape AND glass- I'd ignore the tape if so), apply your fillets, perhaps wait an hour, then place your pre-cut cloth into the cockpit, smooth things out with a dry brush, gently press the centerline into the center "keel" fillet, and start wetting with your squeegie.

To avoid pooling, once the glass is fully wetted, tilt your spreader low, apply modest pressure, and drag it across the glass from areas that are done, to either the edge (shear) or to uncoated areas. Look at the glass and apply this technique especially to any areas that are glossy and slick looking. When done, there should be a uniformly clear appearance to the glass, but with a cloth-textured, matte finish.

RE: First glass - looking for tips/advice

Hi Lou - I'm in Crystal River - about half-way up the west coast - a LONG way from Stuart.

So I have conflicting advice on starting from an edge or starting from the middle when glassing the cockpit.  Maybe I'll get a tie-breaker.  Didn't get to the cockpit today.

It took me all day today to fillet and tape the fore and after compartments.  Had one unfortunate mishap.  I'd mixed up half-cup quantities of slightly thicked epoxy before for doing the puzzle joints, the "spot welding" and the hatch sills - no problem.  And I'd mixed up 2-cup quantities of peanut-butter epoxy for doing fillets - cup of epoxy and cup of wood flour.  Also no problem.  Today after filleting the forward compartment, I thought it would take about a cup and a half to wet out the three pieces of tape in the forward compartment and have enough left to paint the wood.  So I made that much.  Bad idea!  After a few minutes it got really hot.  Damn near melted my plastic cup.  And of course starting hardening in a hurry.  I tried to get the most use out of that I could.  Also a bad idea.

The end result is that about 2 ft of my 3.5 ft length of tape over the bottom panel to side panel joint has significant white spots along the length.  And several pretty thick drips along the way too.  The while spots range from thumb-nail size to pinky finger-nail size.  There are a dozen or so.  I wised up and made smaller quantities after that and the rest of the taped joints I think are fine.  So what to do about this one?  Thinking of just biting the bullet, going after it with my 60-grit paper and taking it back down to the wood and just starting over for those 2 ft.  

Any less drastic fixes?

Also, the bound edge of the tape makes a noticeable ridge.  I'm not in a hurry.  Thinking of sanding that down more-or-less smooth before applying the second skim coat.  Any thoughts on that?

Thanks in advance.



RE: First glass - looking for tips/advice

Actually, no, I didn't mix them up. I'm sorry to hear that one can't start on the sides, though. Guess I'll be throwing away a couple of boats. :-)

Seriously, I've never had any trouble starting on the sides and working toward the bottom. If the cloth gets too mobile, some clamps will hold it in place until it's wet out. Once it's completely wet out, a few passes of a gloved hand smooth out the wrinkles and make sure that the cloth is in contact with the wood everywhere. As long as it's slow hardener, there's lots of time for adjustments.

Is it for everyone? No. In fact, I stopped doing it that way, too. But it does work.



RE: First glass - looking for tips/advice

I have read all the are my thoughts...

first, just to confirm, in the cockpit area where you are glassing the inside of the hull, you don't need to do fibreglass tape and glass the inside of the cockpit.  you just glass the inside of the cockpit.

second, my preference is to do the fillets for the cockpit and the glassing of the cockpit in a single day.  i usually do the fillets in one session...take a break for an hour or two and then do the glass.  i usually wait for the fillets to be firm so i don't distort them when doing the glass....but before it is hard...sort of a bubble gum consistency.  i would also note that i typically break up my filleting into three sessions.  forward, aft and center.   just to avoid hurrying or biting off more than i can chew and getting stuck

third, for cockpit glass, i put it in dry and poor epoxy into the middle and work out towards the edges using a spreader.  my main reason for that is simply to minimize the possibility of the glass ending up out of place.  i just also find it easier to start working the glass/epoxy on a flat surface to start vs a vertical surface.  to prevent pooling, i am aggressive with my squeegee/spreader to squeeze/scrape off the excess epoxy.  i use a cup with a slice in the lip to clean the spreader after each swipe of the the excess and just work the whole surface so there is no excess epoxy.   i will also 'babysit' this step and maybe come back again after 10/15 minutes after the squeeze off to pick up any pooling expoxy that may show up after you let it sit for a while.

fourth, on the goof-uped glass tape, get a heat gun and heat it and pull off the tape. and use a chisel or scraper to remove the softened epoxy from the wood.  i would not try to sand it off.   anyway, once heated, it should come right off.  be careful not to burn the wood.    learning to use a heat gun in building can help you recover from the typical miscalcs.   i consider it an indispensable tool now having built more than a couple boats.   i also have been doing some 'rescue' boats....these are kits where people got sideways and gave up....and then i pick them up and sort them out.  usually my first work is with a heat-gun just getting everything back to a good starting position....i am impressed with the 'undo' capabilities of a heat gun.

anyway, wish you the best of luck



RE: First glass - looking for tips/advice

Didn't have a heat gun, but did have 60-grit paper.  It made pretty short work of the mangled area.  I have it back down either to wood or close enough to get through the poorly set epoxy.  So I'll lay a 2-ft lenght of tape over top.

Still looking for thoughts about sanding down the edges of the tape prior to putting on the (hopefully) final skim coat of the seams that were not messed up.

And hope to glass the cockpit tomorrow.  Thanks to everyone for their input on that. 

One question - I know from putting tape over the puzzle joints back in the beginning that it is no fun trying to trim epoxied fiberglass once the epoxy is hard.  My razor knife did more chipping and breaking than cutting.  Seems like it might be easier to trim the epoxied glass back a half-inch or so from the top of the side panels before the glue has fully set.  Maybe about 2 or 3 hours in.  Good idea or bad?  Any other thoughts on trimming the glass from the top edge of the side panels?


RE: First glass - looking for tips/advice

timing is everything....and to the extent you start to calibrate things, it is a lot easier to trim the glass from the top edge of the side panels when it is 'plasticy' but before it is hard cured. strong preference is to make cuts, like you are describing, is while things are plasticy.

is that 2 hours or 3 hours?  (or something else?) that's what you will learn as part of building.  a good air temperature thermometer in your work area and noting times will help you develop a sense of timing over time.  and to the extent you can hold things constant (like the temperature) you can make it a lot easier to manage your day.

if its plasticy, you can simply and easily cut it flush to the top of the don't need to leave it proud 1/2 inch.

if it is hard cured, i would actually trim/cut it with 80 or 100 grit paper with my fingers properly protected behind the sanding block (you can also use a file) and eye protection.  to try to use a knife once it is hard cured, is a waste of a blade and a chip in the eye or slash your finger open hazard.

anyway...just my 2 cents


RE: First glass - looking for tips/advice

Glassed the cockpit of our Shearwater Sport a couple of days ago.  hspira's tip about trimming the cloth while the expoxy was still "plastic-y" was spot on.  Took my razor knife to the excess about 3 hours in and worked like a charm.  The epoxy was set firm enough to hold the cloth, but still easy to cut.  Also discovered what a wonderful tool the yellow plastic squeegee is.  I druzled small amounts of epoxy from the mixing container (one- or two-cup deli-type containers from Dollar Tree) and worked it in with the squeegee.  Worked very well.  Took a little over a cup of epoxy to do the whole cockpit.  I was pleasantly surprised at how precisely I could bring the epoxy to the top edge of the side panels and how little excess ran back to the middle.

Today I repaired the 2-ft section of tape in the forward compartment that I'd messed up earlier with the smoking and curdling epoxy I mentioned a few posts ago.  I'd removed the offending section with 60-grit paper and smoothed everything out with 100-grit.  Looks good now.  I had some epoxy left over, so I applied it as the second coat to the good sections that I'd taped and epoxied earlier (after 100-grit sanding the edges of the tape).  Used a brush to apply and the squeegee to remove the excess.  Seemed to work very well.  I'm now a big squeegee fan.

So tomorrow I'll smooth out the tape edges on the aft compartment and the new section of tape in the fore compartment and apply a second coat of epoxy there and to the cockpit.  How best to do that?  Just keep druzling from the mixing container or use a foam roller?  In either case, I'm thinking the best course is to follow up with the squeegee to remove the excess.  I assume that the least epoxy is the best way to go, yes?  Should the second coat be sufficient to "fill the weave" in the cockpit?





RE: First glass - looking for tips/advice

A foam roller, followed by tipping out the bubble with a foam brush, is an excellent way to apply very thin coats of epoxy - so thin that you don't need to squeegee them.

Using the roller method, it usually takes me 5 coats to fill the weave. The upside is that then there's almost no sanding needed before varnishing because there are no drips.

If you're going to be painting instead of varnishing, you can fill the weave with a phenolic microballoon/epoxy mix. It's lighter and cheaper than a straight epoxy fill. It's also much easier to sand. Depending on how thick you mix it, one or two coats is all you need. Thicker fills faster but is harder to apply - tends to curl up instead of laying flat. A squeegee is the best way to apply the stuff.

Have fun,




RE: First glass - looking for tips/advice

Thanks Lazlo.  This is for the inside, so no paint or varnish, right?  Planning to varnish the outside.

Five coats!  Wow.  Must be REAL thin going on.  I assume I can do the same thing on the interior wood for waterproofing?




RE: First glass - looking for tips/advice


When are you going to write the book?  You could have saved me a lot of mistakes on my first stitch-and-glue build.



RE: First glass - looking for tips/advice

I don't think I've actually said much that is original with me. I'm pretty sure that others have been saying it longer, so there didn't seem to be much point in a book.

Thanks for the thought, though. And if someone really wants a book, send money :-)



RE: First glass - looking for tips/advice

It's been a while, so a brief update for any who may be interested.  Put two more foam roller epoxy coats on the cockpit of our Shearwater Sport after the initial squeegee coat.  Then sanded with 100 grit to "knock the tops off" the weave.  Then applied one more foam roller coat, with foam brush tipping of the bubbles.  Looks very nice!

So now the interior of the hull is done and I'm about ready to glass the interior of the deck.  It was filletted a few weeks ago.  However I find that the front half of the deck, where the convex curvature is most pronounced, has "sprung" and is about an inch wider than the hull at 60 and 80 inches back from the bow.  The back half is spot on. 

Thinking about using a couple of kayak tie-downs straps to cinch up the front part of the deck to the proper width and then proceed with the glassing.  It suppose it will be a bit of a pain to work around the tie-down straps, but doesn't seem like it should to that big a deal. 

Good idea, bad idea?  Is an inch of excess width enough of a problem to worry about?  If I don't cinch up the fore deck, will the glass make it harder to bend the deck around the forward bulkhead when I glue the deck and hull together?





RE: First glass - looking for tips/advice

i had a similar concern when i was putting my shearwater together.

the approach i used when glassing (and filleting) the interior of the deck was to tape it back to the hull (with strapping tape) after the epoxy was set/not sticky anymore but not fully cured.

by glassing the interior of the hull ..i mean the initial glassing plus the fill coat (maybe 10 to 12 hours in total (6 for the glass plus 6 for the fill coat).

my general approach was to always keep the hull and deck together.

i still had to use strapping tape to hold it all together when we made the final hull/deck join.....but i did not experience any significant problem pulling them into alignment.

not sure if it made a difference.....but certainly made me feel better to know i was not locking it into a shape that was not the ultimate shape i wanted it to be in.



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