Diluted epoxy for first coat on the whipping

kingf000

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On the basis that the strength of a resin is dramatically increased with the addition of some fibrous support, for the optimum strength of whippings you would need to make sure that the resin deeply penetrates the whipping thread. I stripped off some rings recently where I had applied normal thickness of epoxy resin to the whipping and noticed that the epoxy had hardly penetrated the thread. So on the last couple of rods I've made I diluted the first coat of a slow curing epoxy resin for the whippings with toluene (care, good ventilation) in about 1:1 ratio of toluene to resin (Sensei). This is a much greater dilution than recommended with, eg IPA or actone. This mixture seems to have deeply penetrated the thread and so should be stronger, though I have no actual data to support this. A down side is that it dramatically changed the colour of my thread from a grass green to a dark brown! I doubt if colour fasts would help as they probably, and I'm guessing here, work by preventing the epoxy from penetrating the thread! Diluting, at least this, epoxy with toluene didn't seem to affect the hardness of the resin, as it set hard and I was able to sand down any imperfections. The rest of the layers I built up as normal.
 

original cormorant

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I don't want to rain on your parade but why did you want or need to do this?

I never recall a problem with the strength of epoxied or varnished whippings so I don't understand the need to strenghten them. When replacing rings I have found it a good thing that once cut whippings will peel off easily.
 

kingf000

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I don't want to rain on your parade but why did you want or need to do this?

I never recall a problem with the strength of epoxied or varnished whippings so I don't understand the need to strenghten them. When replacing rings I have found it a good thing that once cut whippings will peel off easily.
Because you need fewer layers of epoxide, I've been using just 2, thus reducing the weight.
 

easker1

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I have old rod bits that are just varnished, and have lasted for many years the wraps are in good condition , so why are we so obsessed with Epoxies? easker1
 

kingf000

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Ok, but in your original posting you said "The rest of the layers I built up as normal. ", which implied at least 3 coats.
Yes, I originally used 3 layers but have now decided 2 is sufficient, for me at any rate. You can build up a reasonable amount with the diluted epoxy, rub it down and finish with a top layer. I haven't replaced the rings yet so I don't know how difficult it would be.
 

kingf000

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You can use what you like!
A more considered response (?). I suspect epoxy is widely used because that is what most of the rod manufacturers use, so we are following their example. Correctly used, epoxy resins are much stronger than traditional varnish, so you can get away with less resin. However, the rod manufacturers still put loads of epoxy onto the whippings to get the high finish. IMO totally unnecessary (from a strength point of view), so I don't do it, but most people seem to think it is aesthetically more pleasing.
 

codyarrow

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Always thought the rod companies would somehow only use one coat of epoxy?
 

easker1

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some of these rods can be over 70 years old with varnish almost as good as new, have a look at some of the early Hardys rods, if you are thinning the epoxy with Toluene can you be sure there is no surface Degradation of the original rod?my thought would to be careful, neat epoxy would be no problem, but adding a thinner ( solvent) might cause problems . easker1
 

kingf000

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some of these rods can be over 70 years old with varnish almost as good as new, have a look at some of the early Hardys rods, if you are thinning the epoxy with Toluene can you be sure there is no surface Degradation of the original rod?my thought would to be careful, neat epoxy would be no problem, but adding a thinner ( solvent) might cause problems . easker1
The polymer used for fly rods is very resistant to toluene. I also tested this before I tried it by leaving a small bit of broken carbon fly rod in toluene overnight - no problem.
 

Paul_B

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I used to spray with 2 pack epoxy, the sales spiel those days was that one coat of a epoxy was equal to 5 coats of standard lacquer, good stuff but it had a scary reputation.
These days I use nail varnish from the pound shop on my rod rings, not as flash but its cheap and its good enough for what I want. :)
 

easker1

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I have worked with other plastics where Toluene is a problem, so I was a bit sceptical,I once had to replace a low pressure compressed air system be cause Toluene was left after the Manufacturing process, I am not a great user of epoxy for whippings, but it's great for a lot of other things easker1
 

kingf000

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Toluene can dissolve some polymers, such as polystyrene, polyethylene and neoprene, but cross-linked polymers are normally unaffected. I first started using toluene as it is the solvent in aquasure, to dilute it for better penetration into the seams of my waders.
 

splinters

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On the basis that the strength of a resin is dramatically increased with the addition of some fibrous support, for the optimum strength of whippings you would need to make sure that the resin deeply penetrates the whipping thread. I stripped off some rings recently where I had applied normal thickness of epoxy resin to the whipping and noticed that the epoxy had hardly penetrated the thread. So on the last couple of rods I've made I diluted the first coat of a slow curing epoxy resin for the whippings with toluene (care, good ventilation) in about 1:1 ratio of toluene to resin (Sensei). This is a much greater dilution than recommended with, eg IPA or actone. This mixture seems to have deeply penetrated the thread and so should be stronger, though I have no actual data to support this. A down side is that it dramatically changed the colour of my thread from a grass green to a dark brown! I doubt if colour fasts would help as they probably, and I'm guessing here, work by preventing the epoxy from penetrating the thread! Diluting, at least this, epoxy with toluene didn't seem to affect the hardness of the resin, as it set hard and I was able to sand down any imperfections. The rest of the layers I built up as normal.
I'm stumped as to why the polymer didn't penetrate the wraps. I used to use Gibbs Poly, a high build and frankly, thick, resin for wrapping rods. When I replaced any rings I always found ridges of hard resin under the wraps indicating that it had penetrated to the blank. this was seriously thick resin btw, never thinned but occasionally slightly warmed. Just a thought, could you be wrapping too tightly? Probably not, it would have to be very tight indeed. No, I'm stumped.
Surprised at the colour change as well, I would have expected grass green to go dark green not brown. Blank colour showing through? Or does toluene destroy dyes? What would the effect be on a painted blank I wonder. Colour preserver would keep your grass green colour and as you say it does so by penetrating the wraps and excluding the resin. You don't need to worry about this as the matrix formed by thread and CP is plenty strong enough for the job in hand. I've overhauled CP'd silk wraps which were over eighty years old and they had held up perfectly. A quick coat of varnish to tidy them and they were ready for the next eighty. If you ever decide to use CP don't forget the water soak test, it avoids much weeping and gnashing of teeth.

S.
 

kingf000

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I'm stumped as to why the polymer didn't penetrate the wraps. I used to use Gibbs Poly, a high build and frankly, thick, resin for wrapping rods. When I replaced any rings I always found ridges of hard resin under the wraps indicating that it had penetrated to the blank. this was seriously thick resin btw, never thinned but occasionally slightly warmed. Just a thought, could you be wrapping too tightly? Probably not, it would have to be very tight indeed. No, I'm stumped.
Surprised at the colour change as well, I would have expected grass green to go dark green not brown. Blank colour showing through? Or does toluene destroy dyes? What would the effect be on a painted blank I wonder. Colour preserver would keep your grass green colour and as you say it does so by penetrating the wraps and excluding the resin. You don't need to worry about this as the matrix formed by thread and CP is plenty strong enough for the job in hand. I've overhauled CP'd silk wraps which were over eighty years old and they had held up perfectly. A quick coat of varnish to tidy them and they were ready for the next eighty. If you ever decide to use CP don't forget the water soak test, it avoids much weeping and gnashing of teeth.

S.
It isn't so much penetrating the wraps, but penetrating into the thread itself, so strengthening the thread/polymer matrix. It probably doesn't matter too much for the wrap on most of the rings, though I've been using a top ring without a collar so a good strength there is probably important, as it probably is on the whipping on the joints. I didn't mind the change of colour, as I never want the colour of the wraps to stand out.
 

ed_t

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There's an excellent rod building tutorial by Stan Massey of Alba Rods on world sea fishing forum.

Long and the short of Stan's words on wraps is the strength comes from the thread. Finer thread and more wraps per inch is stronger. The resins used aren't structural resins but potting compounds to protect and provide an aesthetic touch.

Commercial builders glob it on and the potting compound flows evenly and quickly, then a uv zap cure for quick setting. Quick=cheap for mass production.

As mentioned by splinters the colour preserver prevents resin or varnish permeating the thread. IIRC stan suggests meths is another test for what cp will do before you bite the bullet.
 

splinters

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It isn't so much penetrating the wraps, but penetrating into the thread itself, so strengthening the thread/polymer matrix. It probably doesn't matter too much for the wrap on most of the rings, though I've been using a top ring without a collar so a good strength there is probably important, as it probably is on the whipping on the joints. I didn't mind the change of colour, as I never want the colour of the wraps to stand out.
Right, I understand you now. My belief is this.
The thread, whether nylon or silk is more than strong enough to do the job for you. Here's a simple test. Wrap on a snake or single leg guide but don't apply finish. Now pull it from the blank. The guide will bend before the thread snaps every time. Tip rings with side legs used to be common, still are on some coarse rods. The problems start when movement occurs, gradually wearing through the thread. The finish forms a matrix with the thread stopping movement and preventing this. The actual strength to hold the guide on is from the wrap itself. Ferrule wraps on modern blanks are decorative.
That's how I see it anyway.
Simon.
 

kingf000

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There's an excellent rod building tutorial by Stan Massey of Alba Rods on world sea fishing forum.

Long and the short of Stan's words on wraps is the strength comes from the thread. Finer thread and more wraps per inch is stronger. The resins used aren't structural resins but potting compounds to protect and provide an aesthetic touch.

Commercial builders glob it on and the potting compound flows evenly and quickly, then a uv zap cure for quick setting. Quick=cheap for mass production.

As mentioned by splinters the colour preserver prevents resin or varnish permeating the thread. IIRC stan suggests meths is another test for what cp will do before you bite the bullet.
Re. this and other replies: please everyone, don't be so analytical over this topic. There has been at least one other thread on using IPA or acetone to thin epoxy resins, so clearly some people wish to do this. I was simply relating my experience in using toluene, which can be used at a much greater dilution rate than either acetone or IPA, apparently without compromising its strength or appearance. Whether it is necessary or not is, in many ways, irrelevant. I feel more comfortable with an epoxy resin that has penetrated the thread for increased strength - belt and braces approach - and epoxy is a structural resin. What others do is entirely up to them.
 
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