Measuring Epoxy Glue

[ancient kayaker]

I want to pass on a couple of ideas suitable for the cheap amateur like myself. I didn't see either in Thudpucker's original thread on the same subject which became a bit of a rant toward the end and was closed.

Method 1: buy a pack of small el cheapo party cups. stick one inside another. Use kitchen measures to add water, the amount required for hardener for the amount of glue you need. Use marker to draw a line on the outer (lower) cup level with water. Now do that again for the glue. Toss the wet glass, put a clean one into the calibrated cup, and repeat using hardener and glue. Mix and enjoy!

Method 2: System Three supplies some of its epoxies in cartridges that fit into a standard glue dispensing gun. These measure the hardener and glue in perfect 1/1 ratios, and can be fitted with either a dispensing nozzle for pouring into a cup or a blending nozzle which does the mixing as the glue is dispensed. No doubt other eopxy suppiers have an equivalent.

Method 1 is as cheap as you can get. Method 2 is much more expensive but the way to go IMHO if you need small quantities to be continuously dispensed over a fairly long period of time, such as when filling small gaps in planks using the fairing or gel products. Another example is when preparing a stack of long scarfed strips where you can cut and glue as you go without the pot of gluing going off on you. Method 2 is definitely not for big jobs because of the cost.

Terry

I would recommend the method 1.

Not only is it cheaper, the 1:1 resins are in general not the best choice in technical terms.
That may not be a hindrance on tinkering with small items, but on structures I would prefer a better resin system.

West has a pump system for reliable (as it can get) resin / hardener supply. But that is expensive too. And West is not the cheapest resin either.

My 2c of course.
Richard

[duluthboats]

I use 2:1 resins a lot some 1:1, never had trouble using these. You don't need a degree to mix epoxy. Most problems come from poor mixing or the resin not right for the temp.

[W17 designer]

Hi guys
You might be interested in the mixing method I now use most frequently, since I often find that the standard pumps are not only too slow, but can become unreliable in the quantity they pump after a little use. It's detailed in my 'Construction Tips and Techniques' section on my website about Small Trimarans.
Go to www.smalltrimarandesign.com, then select 'Construction Issues' at the left and you'll see the Index for many tips I've posted there.
Another one that I'll detail on the site later on, is a very versatile applicator, especially for doing interior fillets of thickened epoxy. Using a 'popsicle stick' or 'tonque depresser' is the standard way of depositing your mix, but its so S - L - O - W and messy!
Use the 12" disposable cake icing bags and a 1/4" tip, that you've ground with a 30 degree bevel. No mess and great control and about $6 for 20+. WEST have empty cartrides you can fill and then use with a standard cartridge gun. Though this also works, it takes more working space than my icing bag, is more expensive and is harder to load and to clean.

hope this helps someone and enjoy the site ... there's now a wealth of free info posted there.
mike

[ancient kayaker]

Originally Posted by apex1

... the 1:1 resins are in general not the best choice in technical terms ....

Can you provide more information? I haven't heard this before and I use 1:1 systems mostly.

[W17 designer]

Sure ... go here and click on 'Measuring Epoxy'
http://smalltrimarandesign.com/Trima...tion-Tips.html

mike

[PAR]

Yep Terry, 1:1 resin systems aren't typically desirable for marine uses. They tend to be missing the modifiers and other agents to provide the physical qualities we need. The 1:1's are fine for tacking things and lightly loaded pieces, but I'd not want to do seams, laminating or sheathing with them.

If you're still looking for an inexpensive goo, try Marinepoxy. It's 2:1, as non-blush as you can make a resin system and has physical properties comparable to System Three's base resin.

The cartridges used by West System and System three have replaceable mixing tips. These tips are the crux of the problem with these systems, they don't do a very good job. West System has just redesigned their tips and they do work better, but they require a lot more pressure to operate (by hand). Now, I use a pneumatic caulking gun, but those that have the hand operated guns will be hard pressed to get all of the goo out of the tip before it kicks off in the confines of the tip. Personally, I've never had a need for an epoxy squirting caulking gun. Some folks like the cake decorator's bag trick, again I haven't found a need for this and it just shortens up the working time, because you've massed a bunch of epoxy in a bag, which is the easiest way to get a batch to kick before you want.

[W17 designer]

Yes, good advice from Riccelli about the 1:1 mixes .. and his reserve over the WEST nozzles. I only used the latter once because the goop cured in the nozzle - not sure if it was a first or second design though. Cleaning the tube takes time and I don't think it would serve more than twice - 3 times max.
I should have been more specific about my cake icer application. The bags come in all sizes and I use the small 12" one but nothing like full of course ... perhaps 6-8 oz at a time and as the mix is typically thinner than a cake mix, you can empty the bag way before it goes off if you use slow hardener and the work area is 'cleared for action'.
Its certainly a LOT less messy than pasting it on with a stick and for me at least, saves a lot of clean up time scraping off what went in the wrong place in the first instance ;-)
Worth a try to see whether you like it anyway.

mike
www.smalltrimarandesign.com - for Free tech info

[ancient kayaker]

I haven't tried the West cartridges but I didn't have a problem with the S3 cartridge, operating pressure or mixing. the 1:1 S3 epoxies seem to tolerate minor mixture inaccuracies. However that was only one small bottled lot and the one cartridge.

The tips are supposed to be disposable, and the cartridge had a plug that I replaced after each use: I put a little grease on it to be sure. I finished the cartridge without having the contents set up, but it ended a lot sooner than than I expected, due to internal construction I assume.

I have used up my S3 supplies: I did not do any comparative strength tests on them as I did not know at the time that there was an issue. None of the boats I was building at the time have had any problems with seams: I only use epoxy on the last below-the-waterline seam, and have used Titebond III elsewhere. Also I do not glass/epoxy over hulls as I don't see the need.

[PAR]

Once you look up the prices for Marinepoxy and compare it to what you've been paying you'll cry.

Which System Three products are you using Terry? All Silver Tip products are a 2:1 by volume, except their MetlWeld a specialty premixed glue, which is 1:1. Their base resin system is a 2:1, as are their clear coat, surf board and table top resin systems.

Several of their specialty products are 1:1, like: T-88 adhesive, the Quick Cure line, SculpWood Putty, etc. Even their Rot-Fix is 2:1. Knowing this makes me wonder what you've been using.

[Landlubber]

...I only ever use the icing bag type for gunwale rubbers, have never used it in construction...what am I missing here...where do you need that sort of goop in construction?......

[W17 designer]

Re Landlubbers concern
You typically need several boat lengths of it on the typical plywood boat in order to make rounded, concave fillets that strength the ply joints and also permit the covering glass to lay close without air gaps behind it. Smaller fillets are also recommended where stringers come against a ply face, as then the finishing coats of epoxy and/or paint are far more likely to stay intact over the years that follow. Epoxy or paint will thin out over any sharp corner so they are to be avoided wherever possible.
As it happens, in just a couple of days I will be posting a Part 2 Article on 'taping joints' on my website, so this may help fill in any gaps on this.

mike
www.smalltrimarandesign.com

[ancient kayaker]

Paul, I was using T-88 and Gel-magic. You're right about the price, about 1/3 what I paid, although I wasn't that interested in price at the time, just wanted to try some decent epoxy. I added a marineEpoxy supplier to to my database. However, I use very little on a typical boat: the 1 qt of T-88 did 2 canoes and Dace, and I noticed I still have a tiny amount left. That's good as I want to try out an idea for cutting finger joints in plywood without CNC.

W17, the amount of epoxy needed for filleting in S&G is the reason I developed my wood chine log method. I only use epoxy for sticking things together.

[Landlubber]

W17...ah, no worries, you are referring to filletting and radiused corners, OK ta.