Loctite 406

pametfisher · 12-21-2008, 03:26 PM

A fisherman from Australia, Max Garth, wrote a great research posting called Me and GSP. It is long but has a wealth of information about Spectra and Dyneema braided line that I haven't seen anywhere else (link at the end if you're interested). One of his conclusions is that any knot in Spectra can be brought to 100% with the addition of one drop of Loctite 406.

Loctite 406 is a very thin cyanoacrylate (superglue) that wicks into the knot. Although it doesn't bond to Spectra, it penetrates all the microscopic spaces in the braided line and it has a very high shear strength. Some believe that the drop of glue keeps the knot from slipping. It certainly reduces Stress Concentration at the first turn in the knot which may be the larger effect.

I have meant to test this idea myself for a while. Here are the results I got today:

Daiwa PE4 55# 8-strand Boat Braid
Actual Breaking Strength (ABS): 54#
Overhand Knot Breaking Strength: 33# (60%)
8-turn Uni Knot Breaking Strength: 38# (70%)
8-turn Uni Knot plus one drop of Loctite 406 Breaking Strength: 54#
100-turn Bimini Twist Breaking Strength: 54#

The Uni Knot is tied to a 150# coastlock swivel. I only made these measurements once or twice which is not a large sample. My margin of error is 2.5 pounds which could mean that any % could be reduced by 5%.

Me and GSP

Bellyups · 12-21-2008, 11:11 PM

Thanks for posting the information. I will give it a try.

lordhell · 12-22-2008, 12:23 AM

Can you get this stuff at a local home depot or something? I don't seem to see it listed on homedepot.com though.

pametfisher · 12-22-2008, 05:35 AM

Quote:

Originally Posted by lordhell

Can you get this stuff at a local home depot or something? I don't seem to see it listed on homedepot.com though.

I had to search for it on the web. Finally I bought a small tube on Amazon from Techni-Tool, $4.75. Loctite makes a range of cyanoacrylate glues, the key is that this one is the lowest viscosity so it penetrates the spaces in the knot.

The guy who came up with this idea, Max Garth, has fished it for years, including multi-day soak testing in his pool. One thing he stresses, more is not better. One drop, at the mid-point of the knot is the right amount, according to him. That's what I tested.

BretABaker · 12-22-2008, 08:02 AM

pamet - have you tested what regular superglue does? i'm just wondering how big of a difference this makes. ive always used regular superglue with good results, but if this is significantly better that's good to know.

thanks for testing all this stuff by the way

fish4stripers · 12-22-2008, 08:14 AM

Pamet,

Great info. Have you tried braid to mono or fluoro, uni to uni with the loctite?

pametfisher · 12-22-2008, 08:31 AM

Quote:

Originally Posted by BretABaker

pamet - have you tested what regular superglue does? i'm just wondering how big of a difference this makes. ive always used regular superglue with good results, but if this is significantly better that's good to know.

thanks for testing all this stuff by the way

Bret, The key with Loctite 406 ($4.75 for a little tube) is that it is low viscosity (watery not syrupy) and so it wicks through the fibers. Max Garth, the first to bring this idea to my attention, has said that thicker superglues don't work because they don't wick in, they just sit on top.

I bought my tube on Amazon from Techni-Tool.

Interestingly, even Loctite 406 doesn't bond well to Spectra (unless you buy the surface activator which is why Jerry Brown glue is two steps). However, because it fills all the voids, it forms a plug through the knot.

To me, this means that you could connect two Spectra lines, uni to uni, and get a very strong connection.

Max is very specific about only using one drop in the middle of each knot and he has used this for years. You don't want the blob of glue to get too big and too brittle.

I appreciate your comments, I've got several more things in the works.

BretABaker · 12-22-2008, 08:34 AM

thanks, great info.

the super glue ive used is not viscous as far as super glues go (I think), but im going to buy the 406 just to see how much less viscous that is. interesting that the glue doesnt bond to spectra. definitely did not know that.

have you tried the stuff on a P.R. knot? i always dab some on my half hitches at the end....i'm wondering how big of a difference it makes.

pametfisher · 12-22-2008, 08:42 AM

Quote:

Originally Posted by fish4stripers

Pamet,

Great info. Have you tried braid to mono or fluoro, uni to uni with the loctite?

I have not tried that but Max has.

First, the Loctite 406 does bond to mono and fluoro (even though it doesn't bond to braid without surface activation ala Jerry Brown adhesive).

Max uses this in a system where he puts Spectra inside braided-hollow-core-mono and then he splices that, then puts one drop of glue on the splice. He has used it for years and extensively tested it.

Let's say were were using uni-to-uni for a braid to fluoro leader connection. Here are my thoughts:

After making and pulling tight both unis in your normal way:

--put a drop of glue on the braid uni, this will take the the stress concentration (and any tendency to slip) out of the braid knot. It will also attach the braid uni to the mono/fluoro line.

--leave the mono/fluoro uni alone. the loctite won't penetrate to the core of that knot so it won't take the stress concentration out of its first turn.

If you can tell me more about the knot you had in mind, I might have some further thoughts.

pametfisher · 12-22-2008, 08:55 AM

Quote:

Originally Posted by BretABaker

thanks, great info.

the super glue ive used is not viscous as far as super glues go (I think), but im going to buy the 406 just to see how much less viscous that is. interesting that the glue doesnt bond to spectra. definitely did not know that.

have you tried the stuff on a P.R. knot? i always dab some on my half hitches at the end....i'm wondering how big of a difference it makes.

If you put your superglue on a knot and it quickly wicks in, then it might work. This 406 is pretty thin but even it sat on top for a moment and then rapidly wicked in and seemed gone, none on top.

Funny enough while I was responding to fish4stripers I was thinking about the Mid and P.R. knots.

My first reaction is that I would not use it on those knots. Here are my reasons.

--The strength of those knots (and they're about 100%) comes from two things: 1. As you pull on the main line, it grabs the fluoro even tighter. 2. Because the angle between the main braid line is low, there isn't stress concentration build-up as in "normal" knots. If you put glue on it, it might interfere with the normal continuous tightening of that knot.

--The purpose of the half-hitches is to be a fulcrum for the main line to work against as the knot pulls up. If I could get the glue on them in such a way that the main line would still slide through them, that would be okay. But the 406 wicks so fast that I think it would get everywhere.

For these knots, since the half hitches on the fluoro are the fulcrum and the half-hitches on the main line hold the other half-hitches from coming loose on the fluoro, here I think a thick super glue that sits on top of the tag end of the braid would be good to keep the second set of half-hitches in place. (I use it on Biminis that way.)