I think it's the "microbubbles" that Scott mentioned.
I examined, under magnification, the cured excess polymer slabs that I saved from my application pan. They are all clouded with very tiny air bubbles on the surface.
Then I examined the polymer samples that I kept from a few previous rod builds, and none of them have tiny bubbles on the surface.

This is only the third rod I've built with Flex Coat Lite. I did a couple of things differently this time. I did not warm up the polymer bottles before I mixed the parts together, because I did not like how warming it shortens pot life. I work slowly. Secondly, I blew through a straw, onto the polymer in the application pan, which popped all the visible bubbles, because they did not disappear on their own, like they've done with previous builds. I noticed that created a slight hazy film on the polymer, which I've never seen before on any previous builds (I've built 8 previous rods.)

I also used the straw to blow onto the polymer on the rod, as a final touch, to make sure I hadn't missed any bubbles with my flaming. I also thought the warmth from my breath woud help even out the polymer. I noticed this produced a bit of haze on the surface of the polymer. Then I left the rod turning for about 8 hours, and didn't remove it from the turner until about 18 hours. Every surface of polymer was crystal clear and as glossy as glass. I was so pleased. One section has rested, undisturbed, for 6 days, the other section (2 piece rod) for 4 days. I do not know when the "microbubbles" appeared, but I think just in the last day, because I checked yesterday, and the polymer still shined like glass then.

The only other concern I had was a lot of bubbles became entrained in the polymer when I mixed the two parts, but I don't think any more than in my previous builds. And, the bubbles all dispersed in the application pan, before I applied the polymer to the rod.

I hope this additional information gives you more experienced rod builders some clues as to what happened.



Edited 3 time(s). Last edit at 12/28/2012 12:02AM by John Segal.

sounds like improper mixing to me. probably not enough part B hardener.

Randolph, could you please clarify if you mean it was improperly mixed due to unequal parts, or some sort of improper mixing, PLUS unequal parts?

Do you think I stirred the parts too vigorously, or not long enough? I think I mixed for about 4 or 5 minutes.

I'm sure I used equal parts of resin and hardener. All my mixing is done with the syringes that come with Flex Coat kits, and I am extremely careful to make the parts equal. I understand that too little hardener could result in an incomplete cure resulting in softness, but in this case, the cure is complete. It was hard within half a day.

Well, the time window for fixing this in time for gift giving has passed, so the emergency is over. I won't touch the rod now, until I gather more information on a fix, so I'll be checking this helpful site from time to time. Now it's on to the Christmas thing for a few days. Have a good one, people, and thanks again.

John

John, have you used the finish from the same bottles you are using now before? or is it a new batch? If you used out of these bottles before, I would suspect accidentally being mis-measuring or not completely mixed. If new batch of finish I would suspect a bad batch or contamination of some type. I once used a finish that the mfg gave me at a sportsmans show. I stupidly applied it to an expensive rod for a customer.It turned out well I thought! The first time he fished with it in a saltwater setting, it got cloudy and was so soft it was easily dented with a fingernail. I had to redo the whole rod. But used my standard finish. That finish maker was out of business in 6 months.

Randolph, thank you very much for this extra help. What a terrible experience you had with that saltwater rod! I sure would not want to redo a whole rod. I once replaced just one guide wrap, and that was not a good experience. I do not use colour preserver, so my polymer bonds extremely well to the blank.

To answer your question, I used a new batch; Flex Coat Lite, with a label that says "Improved Formula Ultra V UV Protected." I will ask my supplier if he has had any other customers with this problem.

I remembered one other thing. I used the brushes and stir sticks that came with the Flex Coat kit. And I used the same stir stick for all mixes on this rod, but cleaned it well between, using U-40 brush cleaner, then isopropanol. That's the only possible source of contamination I can think of.

I guess after Christmas, I will try sanding down the bad surfaces with 400 grit paper, then add a thin top coat. But I think I might use another brand of polymer to do that. I have no idea which brand, but will do some research.

Thanks again, Randolph.

speed up the drying if you are going to polish it , put it the warmest part of the house to help the drying time some , an I don't mean "" high heat "" 75 deg would greatly help a lot in my part of the world
the heat means a lot , [ ALASKA } then polish it out if not cut it off an do again now as the Flex coat will only get harder over time , so make your mine up now what you are going to do

Just for your information, and I am not saying anything against any other Manufacturer, but in over 30 years of using Trondak finishes I have never had one problem. I tested Perma Gloss, Dura Gloss, and the CP against every other brand for years. I hung rod sections on my backyard fence for years to check for yellowing, weather and sun damage, etc. Trondak won hands down!!

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Edited 2 time(s). Last edit at 09/20/2016 05:23PM by John E Powell.

The hazing you mention when blowing on the epoxy is most likely moisture from your breath. Moisture and uncured epoxy can be a problem, not sure that this caused your situation. Also the mixing time seems excessively long, and if it was vigorous you probably introduce the micro bubbles.

I agree with Phil.

I dislike blowing on finish because of the potential to introduce moisture from your breath.

The only thing that I do is to use equal parts of part A and part B.

Then I mix slowly for at least 120 seconds or two minutes. This time will insure an excellent mix.

After applying, I use a bit of gentle heat if needed to allow the finish to flow, or to remove any bubbles that might have gotten into the mix.

I also leave a space heater on in the drying area to keep the temperature in the area at about 80 degrees.

By keeping the area at 80 degrees, I can normally apply finish in the evening and then pack and ship by noon the next day.

Good luck
Roger

Sorry to hear your rod won't make an appearance for Christmas. Do a test sometime...In a heated room it would have been finished in under 24 hours (likely way under). I have put up to 3 coats on a single rod in one day. Two coats is no problem at all. One coat and you're fishing tomorrow (so to speak).



Edited 1 time(s). Last edit at 12/23/2012 07:27PM by Jay Lancaster.

Roger gave good advice.Especially about the space heater, if it doesn"t have a fan to create dust in the air. If you use a single urethane finish like Perma Gloss a decent amount of humidity in the room will be more beneficial than heat. But a nice warm room for epoxy works optimally.

I really appreciate all the help from you guys. This is such a great forum.

I'm pretty sure my mixing time of 4-5 minutes was okay. The Flex Coat company has a video online, which recommends 3-6 minutes, depending on air temperature. (The higher the temperature, the shorter the mixing time.)

I am undecided about moisture, because I've read conflicting advice. Some say humidity affects polymer performance, and others say it does not. Many people use a straw to blow moist breath onto polymer. I didn't use the straw on my first 5 or 6 rods, and they came out fine, although I used a different polymer on those. I did use a straw on the rod just before this one, and it turned out very well. I used Flex Coat Lite on it, as well.

I am cautious about heat. I heated the polymer parts prior to mixing, on my last rod, and it made the polymer flow nicely, perfectly penetrating the threads, but it also set up too fast for me. I work very slowly and carefully. Also, my rod turner makes me apply polymer very slowly, because it only turns at 5 rpm (BBQ motor). So it takes a long time for me to coat each wrap. For example, it takes me two batches of polymer for a fly rod tip section that has about 7 guides.

About the only thing that I will definitely change in the future, is to throw away my stir sticks after each mix. The reason I re-used them this time, is because I really like them, and didn't want to waste them. They are the round, plastic ones that come in the Flex Coat Lite kit.

I'll be mostly offline until after Christmas, and after the festivities, I'll try to fix the blemishes on the rod, and let you know how that went.

Thanks again, everyone!

Oh yeah, one last question. If I do the fix by sanding down the blemishes, what polymer is recommended to recoat? More of the stuff that's already on (Flex Coat Lite), or something else? I was wondering about something very thin, like Permagloss, which I've never used before. I'm thinking that a different coating might not adhere well. True?
Thanks again.

Perma gloss will work well, but only if the Epoxy is fully cured and no longer soft. Otherwise it will just seal a problem.

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Edited 1 time(s). Last edit at 09/20/2016 05:23PM by John E Powell.

John, you have been given many great suggestions. As someone just getting back into this, and therefore a little new to epoxy thread coatings, I'll add a couple more based upon your comments.

"I examined, under magnification, the cured excess polymer slabs that I saved from my application pan."
Okay, if you have a slap in your application pan that points to a couple of things wrong. The thicker the slab the faster it will set up and you state that is a problem already. I suggest you mix the epoxy as normal, let it rest in the cup for a minute more, then pour it out on a saucer covered in aluminum foil. Once of the foil blow it around with a straw to release bubbles and have a very thin coating. You can even shine a halogen lamp on it to thin and help release bubles. The thin coating will release bubbles better and extend pot life.

"I work very slowly and carefully. Also, my rod turner makes me apply polymer very slowly, because it only turns at 5 rpm (BBQ motor)."
IMHO you need to change that. If you apply that slowly you are almost certainly painting rather than flowing the epoxy on. You want to load your brush, lower to the blank so only the epoxy makes contact, then give a quick turn of the blank by hand. it only takes a fraction of a second so you won't have as much time to shake/mess up. Buy a wide enough brush that one turn gets it done. Start at the tip and move on to the next guide immediately. Once finished, let the blank sit and wick of any extra epoxy as needed, rotate 180 degress and repeat. Another reason not to apply on your dryer BTW. Grab your lamp and magnifiers and look careful at each wrap, rotating and blowing out bubbles as needed. If you like use a bic lighter, alcohol torch, or a propane torch but I don't feel the need for such things normally. But hey, I live where it is hot and I'm paranoid about the AC stirring up the dust. If I can do an eight foot saltwater rod with double foot guides in one batch, in a 90 degree room....well you can do a fly rod. You have to trust that less is more and the more you touch the epoxy with the brush the worse off you are. Get it on as quick as possible, turn by hand for the first 5-10 minutes, wick off the extra, make sure everything is coated, make sure the bubbles are gone, then move it to the dryer and walk away.

Do not use iso alcohol as a final cleaning step. It is only about 70% pure. I like plain soap and water. If you feel you must use alcohol go buy the 99% pure technical grade. It is cheaper and can be ordered from McMaster Carr. I use craft sticks from Micheals to mix with. I feel they get into the corners of the mixing cup better. Read literature from those that make epoxy to help you decide about things like humidity and heat. And most important of all....once you find something that works for you stick with it. Each brand/formula has a learning curve. Find what suits your needs and do things the same way each time. If you decide to try a new product/technique then do so in a test and not a real build.

Russ in Hollywood, FL.

Russ has some great points.

Just a thought -
I buy my alcohol, xylene, mineral spirits, and lacquer thinner from the paint department of one of the big box home lumber stores.

They have excellent prices and the quality of the products is " very high - paint grade products".

For craft sticks, I use popsicle sticks. I happen to buy popsicles by the box, so after eating the treat, I take the stick in to the wash room, wash it off - and let dry.

To prep for mixing, I use my chop saw to chop the stick off square. Then, I use my belt sander to slightly round the edges of the cut end of the stick. The flat end makes for excellent mixing and the slightly rounded corners let you get into all of the corners without cutting into the cups.

After I mix a batch, I use a paper towel that has been wetted with Alcohol to wipe off the excess finish on the stick.
By the time that I get around to mixing another batch, all of the alcohol has evaporated and is ready to use again.

I am still using some of the same sticks from several years ago. Each of these mixing sticks have a nice thin coating of finish on the sticks due to use, and now have no issue in getting splinters into the mixing cup.

As Russ pointed out - get the finish on the guides in a hurry. Use the method he suggested if you wish.

I happen to use my power wrapper to apply finish at speeds up to 300 or 400 rpm. Most of the time it is about 100 rpm. The nice thing about the foot controlled power wrapper to apply finish is that you can instantly stop the rotating rod anywhere for filling in on the edges of the guide foot, or into the guide tunnel.
Then, hit the pedal again to do a quick spin to clean up the edges and then move onto the next guide.

As Russ suggested - when applying finish quickly - no reason to have to mix up more than one batch of finish for the rod.

I personally mix the finish in the cup, and then apply finish out of the cup. I mix, apply finish to all of the wraps and guides very quickly. Then, starting from where I started, I will slow down, and use my heat gun to apply heat anywhere that I might find a thick spot or any bubble in the finish. The heat gun thins the finish and lets all of the bubbles escape from the finish at the same time. Again, great care must be used to avoid overheating the finish.

I just did a bunch of rods a few days ago, and for kicks did some stop watch times for applying the finish.
I found that from the time I put the brush to the first part of the rod, until I transferred the rod to the dryer was typically about 4-5 minutes.

As Mr. Kirkman has said many times before - don't brush on the finish. Just load the brush, and let the finish flow off the end of the brush to fill the thread and cover all pats of the blank as needed.

By the way, when drying, I typically set my adjustable speed dryer at about 8-10 rpm.
I did a rod sometime ago at 15 rpm and found that I had severe foot balls being generated on each guide. This was with virtually the same amount of finish that I had applied to a different similar rod - where I dried it at my typical speed of 8-10 rpm.
I found that when drying at speeds over about 11 or 12 rpm, that I begin to get a bit of finish slinging and the creation of thick spots or footballs in the center of the guide foot.
Of course different finishes work and cure differently. So, use the system and speed that works best for you and the products that you are using.

Be safe
Roger

Having read all your latest suggestions, I'll be making these changes in my work:
1. Only mix polymer parts for 2 (max.3) minutes. Even though the visible bubbles dispersed after mixing, I suspect that microscopic bubbles remained.
2. Continue using Flex Coat's round, plastic stir sticks, but toss after each mix.
3. Pour the mix onto aluminum foil, to extend working time.
4. Find some way to apply the polymer to the rod much faster, such as using the larger Flex Coat brushes. I've been using their 1/8" brushes, that come with their polymer kits, and I see that they also sell 1/4" brushes. I will also look for a drying motor that is faster than my 5 rpm one. Failing that, I'll try applying without a motor, rotating the rod by hand, until all the polymer has been applied, and then connect it to the motor until cured.
5. Refrain from using heat on the applied polymer, after about 10 minutes. I have a strong suspicion that my application of heat (lighter flame) near the setting-up stage, created those micro-bubbles that could not escape through the thickened polymer.

I am still mystified about why I did not notice these micro-bubbles until several days after the polymer had set up. All of the finish looked like glass when I checked the rod the day after application. Either my observation skills were at fault, or the bubbles somehow formed within hard polymer, but I don't see how that is possible.

I'll try to link to some photos again:

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Thanks very much, everyone.