More hand-holding, please

Submitted byorourkmw onFri, 08/17/2018 - 09:00

 I had previously posted about bugs in my seal coat, but after gentle scraping and laying out and wetting the fiberglass, the bug spots areas were not too much of a problem. However, on my first fill coat, I was applying an abrasion football patch, and ran into problems.  I had cut the fiberglass for the patch carefully on the bias and placed it right to the chines.  When  I started putting the epoxy on, in spite of being gentle,  the edges frayed and unraveled and in some cases snarled.  I tried to smooth it out as best as I could while I was working the epoxy (tried both squeegee and roller), but it still looks pretty rough this morning around the edges. Will these just disappear with further fill coats?   I may try to scrape the higher ones off, but because I don’t have all the fill coats on yet, I am worried about cutting into the main glass if I have to sand.  Also, is there something I should have done better when cutting the fiberglass? 


Fri, 08/17/2018 - 11:23

Fraying edges aren't that unusual; I think it happens even if you are quite careful.

Even without fraying, cloth edges tend to 'stand up' a bit. There are 'tricks' you can use (PeelPly, plastic) to cover the edges while the epoxy is still wet, but it's often easier to just (hand) sand the rough spots away. As you say, one needs to be careful not to sand into the underlying glass layers.

Other techniques I've used include:

-Wetting out both glass layers at the same time

-Putting the football under the main glass layer (various opinions on this!)

-Putting masking tape on the boat 'under' the new layer and cutting the excess glass away while the epoxy is still 'green'. This takes careful timing. I think Etienne Muller has some good instructions and pictures on doing this as he wraps the deck glass down over the hull.

John VanBuren

Fri, 08/17/2018 - 16:01

With your current situation, I would carefully hand sand or scrape as previously discussed.

I have found the use of masking tape and trimming when the epoxy is "Green" or to put it another way when the fiberglass soaked with epoxy is in a plastic state, to be the best way for me to get a clean edge.

If you are applying a "football" this will mean that the football is installed as a separate operation so you are not trying to cut its edge with a layer of fiberglass under it that is also not cured to a solid state.

I hope this has some value!


John VB


PS The easiest way to determine when the epoxy/glass coat is ready for trimming is to check it every hour or so as temperature, type of epoxy and possibly humidity can cause epoxy curing times to vary  significantly


 I will hand sand the spots carefully before the next coat. The masking tape sounds like a good idea.  I really appreciate the help.  And you’re does play with your nerves!


Scott Innes

Fri, 08/17/2018 - 22:02

As John says, the masking tape approach is best and will work for you next effort.

Instead of sanding, you might find it easier to use a scraper to just feather the edge. It's clean and less elbow grease than sanding.



 I found that the scraper did work well. I could see better without the sanding dust, and found I could be a little more aggressive with it without cutting into the fiberglass. I then finished it with sanding.  If I see this problem again, how soon can I actually start scraping? Obviously it gets harder as the epoxy cures. Can I start just after it is tack-free, or should I wait some? 

John VanBuren

Mon, 08/20/2018 - 07:24

I would use masking tape next time. And wait until the epoxy is no longer tacky to make a clean cut with a razor knife (like a Stanley 99 with a fresh blade).

John VB


Mon, 08/20/2018 - 11:21

If I see this problem again, how soon can I actually start scraping? Obviously it gets harder as the epoxy cures. Can I start just after it is tack-free, or should I wait some? 

Do some experimenting, but I think you will find that if the epoxy is still 'rubbery' it won't scrape or sand very cleanly, but it will cut with a sharp utility knife or chisel.

Rob Macks Laug…

Mon, 08/20/2018 - 16:18

The extra layer of cloth sometimes applied below the waterline is not needed, unless you like to drag your boat.

I stopped adding a below waterline layer 20 years ago. I paddle in rocky Maine and Georgian Bay with no problems.

IF you were to add a layer below the waterline, it should be over the full layer.

You run a very high risk of sanding through the full layer where the "football" edge is, IF you place the football layer under the full fiberglass layer.

If you sand through the full layer at the underlaying football layer edge, you will have compromised your hull strength. DON"T DO IT!

Bias cut cloth is only needed for curved stem reinforcement, or where there are complex shapes to follow. 

See this video for the "tape and cloth edge trim" method to have sharp neat extra cloth layers/ hull deck joint glassed edges.

Please let me know how I may be of further assistance. 

All the best,

Rob Macks

Laughing Loon Custom Canoes & Kayaks


“All things are difficult before they are easy.” - Thomas Fuller

I received your book last week, Rob, and want to compliment you on both your presentation and thoroughness.  I am working my way through your videos, so I appreciate your specific link. The patch was on top of my full layer.  I understand now it is probably overkill!  But I am having fun and learning a lot.


Rob Macks Laug…

Tue, 08/21/2018 - 09:13

WAIT until the epoxy is very leathery before cutting. If it's soft the edge can appear white where epoxy and cloth separate.

Lift the cloth into the NEW utility knife blade. Don't press down and cut through the underlaying glass!

It can be a delicate dance.

Please let me know how I may be of further assistance. 

Live Long and Paddle

Rob Macks

Laughing Loon Custom Canoes & Kayaks


“Persistent people begin their success where others end in failures.” - Edward Eggleston

I always tried to streamline all my methods. I did the football layer on top once and that was the last time for that.

I have done it under the full layer from then on (4 oz cloth) and none of the horrible things that people warn, ever happened. I now only run a piece about 8 inches wide that tapers up to the bow and stern since my paddling experience tell me that's where the abrasion occurs. I do hit things by accident that you can't see under turbulent water. That gets laid up at once all under the full piece. Never had a problem. Easy to do. No ragged glass edges to deal with. Not knocking anybody's method.   If it works and you're happy, that's what counts.

I do a football.  My kayak gear and camera gear is all about the experience and I do not pamper either.  Many would say I am abusive.  When I see used camera gear for sale that doesn't have any chipped paint or scratches (not including the glass) I feel bad for the gear it has never got to do what it was designed to do.   I can't say that I have ever gone through the first layer of glass but there have been several times I was glad there was a second layer.  I have not tried doing the football first but Jay has me thinking about it.  



Wed, 08/22/2018 - 12:11

Like Jay, when I add extra cloth it's under the main hull covering, and it's never caused a problem.

You may think that a single layer of glass is more substantial than it actually is. The first time I laid up glass/epoxy panels for glass bulkheads, I realized how 'flimsy' a single glass layer is.

It all depends on where you paddle and how the boat will be used.

If you paddle muddy rivers or never let the hull of your work of art touch a rocky shore (Et?) then a very light construction is the way to go. 

If your 'beaches' are often low-tide coarse gravel with barnacles, with waves at the launch and landing spot, and you use the boat for trips (with gear inside), you'll be happy to have postponed the inevitable  exposure of the wood core to the sea.

...although probably not my last!  Thanks, Etienne.  I had seen your previous response on masking in dealing with exterior hull and deck tape joint.  I know the consensus is to not use seam tape on the exterior because of the selvedge, but if you mask can’t the selvedge just be cut off?  Or is it also an issue because the tape is not bias cut?  Although I am not at that point yet, I wonder if I am going to have a long enough piece of cloth to be continuous down one side after cutting on the bias.  I am skeptical of my ability to piece together smaller pieces seamlessly in one go.  (Come to think of it, if I am cutting a true 45 degree, wouldn’t Pythagoras reckon I need 5/3 my length - 14 ft kayak would need 23+ feet of cloth if cut on bias?  That doesn’t sound practical, so folks must either not go all the way to 45, or else piece together...unless I’m missing something....)

By the way, I was fairly successful in cleaning up my frayed edges.  Not perfect, but I’ll do better on the deck.  Thanks again to all for the help.

Rob Macks Laug…

Wed, 08/22/2018 - 14:03

I don't understand it. Gravity seems to keep increasing every year. At an exponential rate in the last few years!

So I do everything I can to make my boats as lightweight AND strong as possible.

Right now I'm building myself an Ootek using 1/8" thick Alaskain yellow cedar strips for the hull.

The bottoms of my kayaks are covered in scratches. I like to explore shorelines in Maine and Georgian Bay, so quite a few rocks find me.        

One layer of 4 oz. S-glass has worked quite well for the last ten years. Even with camping gear for a week I've never cut through the glass on a grounding.

So if gravity increases are not an issue for you or you like to drag, go for two. Extra layer = extra weight. Certainly, if you understand the potential for cutting through the step in thickness of the full glass layer over an underlaying layer, you can add extra resin to smooth the transition and sand carefully. "Lerker Alert!"  However a novice might not know to do this on the first boat.

If you go to 4:42 on this video you'll see me go aground, "D'oh" trying to be close to an island.

Please let me know how I may be of further assistance. 

Live Long and Paddle,

Rob Macks

Laughing Loon Custom Canoes & Kayaks


“People who say it cannot be done should not interrupt those who are doing it.” - Chinese Proverb

You only need bias cut cloth on sharply curved edges like stems. Bias cut cloth is hard to handle, wastes cloth and not good for long pieces.

See this video at - 4:17  for details of doing the tape and trim technique.

The salvaged edges of seam tape won't wet out transparently and seam tape is often heavier. Seam tape is too narrow to overlap the tape.

I cut 6" wide strips off my 60" wide roll of 4 oz. S-glass. Make seams 2" on deck and 2" on hull with 1" overlap onto tape on each surface.

You need the extra width to have a good hold as you cut the extra glass away. And wide glass wet out with epoxy (which has no tack strenght) will round the tight hull deck joint better without bubbles appearing later.

Please let me know how I may be of further assistance. 

Live Long and Paddle,

Rob Macks

Laughing Loon Custom Canoes & Kayaks


“I am always doing that which I can not do, in order that I may learn how to do it.” - Pablo Picasso


Nick Schade - …

Fri, 08/24/2018 - 10:23

In reply to by sbaxter

I've done both one and two layers. I have stressed both to the point of failure. I've worn through 4 layers of glass and I've sliced through several layers of glass. I stove in the side of a kayak while paddling.

In my experience, two layers are stronger and more durable than one. You don't need a second layer unless you use your kayak in a way where you might want more ruggedness. Of my kayaks currently on my rack, the ones with one layer on the bottom have more spots where I have sliced through the glass to the wood than those with two layers.

I don't need two layers, the kayaks with one layer where I have severely damaged the cloth still work fine and have plenty of life left in them. I don't bother fixing the slices and bruises until I have enough to make it worthwhile. But, that point takes longer to reach when I have two layers on the bottom. 

If I treated my boats with a little more care, one layer would be plenty for everyday use, but the kayak is a means to get to the places I want to be and as such, two layers provides more protection and requires less maintenance. 


Sat, 08/25/2018 - 12:04

Unless you live in utopia, abrasion is a fact of kayaking. Yesterday I launched in about 4 inches of water. Mud and stones. Low tide and that depth went out about 30 feet before it got deeper and soft mud. I floated fine but had to drag (paddle) the back of the boat off the bottom as I launched. I could not walk out deeper since it was mud. So abrasion is everywhere not just in heroic surf landings.