It is currently 28 Mar 2024, 21:38


New Topic Add Reply
Author Message
Clear guide wrap help
Post 24 Oct 2021, 12:15 • #1 
Guide
Joined: 01/10/18
Posts: 106
Location: US-OH
What’s up guys. I have some questions. I am currently working on a CTS 7wt. It’s a raw glass blank and I was hoping to put clear guides wraps on it. I used white silk (which I used on my epics) and thinned the epoxy with acetone. 1:1:1 ratio. In the garage lighting it seemed to go completely clear however when taken out into sun light, you can tell the thread has a whiteish tone to it. The guides were wrapped with moderate tension. Should I have used a natural color thread instead of white since the blank is lighter? Looking for some input, I don’t hate the outcome, however…it’s not what I was looking for




Top
  
Quote
Post 24 Oct 2021, 12:52 • #2 
Sport
Joined: 02/26/18
Posts: 34
Some white silk (such as YLI) has optical brighteners in it which keeps it from ending up clear. "Natural" silk usually will go completely clear. I make cane rods and use a very pale yellow for my clear wraps because it matches the bamboo better.

Tim


Top
  
Quote
Post 24 Oct 2021, 16:02 • #3 
Guide
Joined: 01/10/18
Posts: 106
Location: US-OH
That’s what I thought. So I did do a test with the natural color silk I had. Two of which were hitena and 1 was fish hawk. I am using flex coat lite with acetone. I’m kind of stumped at this point.


I also found this bag of thread that I may try as well… ;)


Top
  
Quote
Post 24 Oct 2021, 16:40 • #4 
Glass Fanatic
Joined: 12/31/15
Posts: 1238
Location: Northern Rockies
I would try mixing the epoxy without acetone for the first coat. The acetone evaporates out, leaving thread that isn’t completely saturated with epoxy anymore and this not completely clear.

A heat gun or an alcohol lamp is enough to make the epoxy a similar viscosity to when thinned.

My personal strategy for clear wraps is to saturate natural silk with straight epoxy (helped by a heat gun). Once the wraps are completely soaked, I wipe off the rest of the epoxy and let it cure. I then generally use two more light coats of epoxy to finish the wraps.


Top
  
Quote
Post 24 Oct 2021, 18:26 • #5 
Glass Fanatic
Joined: 09/18/09
Posts: 5561
Location: Relocated to the Drought Stricken West.
What was the matter with the middle two wraps? They look pretty good, and from the photo's I can't see any problems.

I also would lighten the thread tension and wash you hands well before starting to wrap.
I agree that you should avoid the acetone and just warm the epoxy to get it to flow. Start at one end of the wrap and move to the other, letting the thread wick up the epoxy.

What prevents the thread from going transparent is air in the thread/wraps. To tight a wrap seems to prevent the epoxy from soaking in. Putting the epoxy on too fast ends up traping air underneath the epoxy. Thinning causes problems because the thinner starts to evaporate, which has the chance of introducing gass bubbles into the thread.

I've done over 20 rods with transparent/translucent wraps (or at least tried to). it takes patience and practice. If I can avoid rushing, I seem to do ok.


Top
  
Quote
Post 24 Oct 2021, 19:29 • #6 
Guide
Joined: 01/10/18
Posts: 106
Location: US-OH
Interesting, thanks for all the help guys. I’ve used acetone with white with good success in the past, which was I was shocked when they came out white. I did do a test with the Pearsall Gossamer thread and I think it had the best result so far. I’m leaning towards re-wrapping with it.


Ignore the sloppy epoxy, it was more for color test purpose


Top
  
Quote
Post 24 Oct 2021, 19:34 • #7 
Administrator
Joined: 01/10/06
Posts: 7811
Location: Holly Springs, NC
When clear wraps are done successfully the threads and finish should look like a clear band without any visible thread. There is a never ending quest on this forum to conquer the secrets of clear wraps - often with the results not meeting expectations. There is a lot of science happening. Bear with me.

Rod wrapping materials are colored, although the colors are not easy to perceive (as merkexpress showed above). In addition, rod wrapping materials have a physical property called refractive index or RI. The RI defines how much light bends when it enters a material. Here's the important part. If your thread and wrap finish are the same color and have the same RI, the wrapping threads will be invisible.

How does an ever questing rod builder get to clear wraps? Practice, test, practice, and test. Take notes. Try different materials. Test some more. Once you have a system, stick with it. Don't wing it. Test any material substitution or new batch of thread/rod finish to be sure.

So what could make clear wraps not so wonderfully clear?
  • Color. Truly colorless thread and finish are hard to find. The underlying rod blank brings another color to the party. Perceived color changes with lighting*. Evaluate your tests outside under the conditions you will use your rod.
  • RI dispersion. Dispersion measures RI changes with respect to the light color shining on the material. In other words, the RI changes as the light changes. Test wraps look different under workshop lights than in bright sunlight or on a cloudy day. Again, evaluate your tests outside.
  • Uncured finish or impurities. Spar varnish color and RI changes as the solvent evaporates and the oils cure. Epoxies change RI during cure (and turn yellow if poorly mixed). Don't evaluate your tests immediately - let them cure for a week or three.
  • The final color and RI of the finish. Varnish and epoxy makers don't publish their color or RI values. In addition, the RI and inherent color differ from company to company. Traditional spar varnish has a yellow cast as does polyurethane spar, but they have different RIs. Different epoxies have different RIs. Test different types and brands of rod finishes.
  • The color and RI of the thread. Thread makers also don't publish their RI values** or the secret sauce in their colors. White nylon and white silk do not have the same RI. Different white threads from the same company are different colors. Don't change threads without more testing.

Most important, be reasonable with expectations. There are many factors to juggle. Your camera shows things your eyes can't see*. Macro-scale photos reveal color and RI differences that are imperceptible when holding a rod at arm's length. Clear wraps are tough to achieve.


Tom

* Cameras see light much differently than our trickster vision. A sheet of white paper under a typical room light might photograph as orange. The same paper outside on a cloudy day might photograph as blue. Our brains know that paper is white, so we will always see white.
** Thread filaments are also birefringent, meaning the RI changes depending on the direction the light hits the thread. This is a minor effect compared to dispersion and color. Bulk RI values for nylon and silk are published, but the birefringence increases as the materials are pulled into filaments and those filaments are spun into threads.


Top
  
Quote
Post 24 Oct 2021, 20:21 • #8 
Guide
Joined: 01/10/18
Posts: 106
Location: US-OH
This was my first ever attempt at the translucent wraps. IMHO it come out more clear then my recent attempt.


Top
  
Quote
Post 25 Oct 2021, 07:26 • #9 
Glass Fanatic
Joined: 04/20/07
Posts: 8920
Location: US-ME
Tom gave you some of the whys. I'll just add that if you want clear on white, no matter what you do, you are going to get cloudy/dingy/or yellowed sooner or later--either the blank, the finish, or both. And they won't go off-white at the same rate. It won't remain pristine. Some contrast between thread and blank is needed to give the appearance of "clear." In other words, if you want "invisible," white might be the thread choice. For "clear," transluscent with a chosen hue might give you what you want. Let's say starting with a light blue thread, or pale red.

As far as the outcome you have, I'd consider that more than satisfactory. Trying to redo it may create more problems in the blank finish than it solves in the wrap finish.


Top
  
Quote
Post 28 Oct 2021, 01:27 • #10 
Guide
Joined: 02/06/15
Posts: 160
Location: Colorful Colorado
You could sell that bag of Pearsall's and retire on the proceeds.


Top
  
Quote
Post 28 Oct 2021, 10:10 • #11 
Guide
Joined: 01/10/18
Posts: 106
Location: US-OH
I’d likely be willing to sell some;)


Top
  
Display posts from previous:  Sort by  

New Topic Add Reply



Who is online

Users browsing this forum: No registered users and 8 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Jump to:  
Google
Powered by phpBB® Forum Software © phpBB Group