Low viscosity epoxy

[Prashun Patel]

I am making some cheese and butter knives.
I am having trouble getting epoxy (System Three T88) into the handle hole.

I prefer to use epoxy because the hole is round while the tang is a thin blade; so I have to use a gap-filling adhesive.

Do you have any recommendations for how to get thick epoxy into the hole, or a good thin-viscosity adhesive that would be appropriate?

It's a standard Craft Supply blade, and comes with a ferrule. Honestly, I think the ferrule looks cheesy ;), and would prefer to route out a thin mortise in two halves and then glue them together, but am unsure if this would be stable.

Any advice???

[Brian Kent]

I agree with the idea of the routed mortise. The joint is stronger than the wood, so if the wood itself would hold, I think the epoxied mortise would too.

[Al Launier]

Prashun, have you tried using a large orifice injector?

[john taliaferro]

Warming it before mixing sometimes thins it . I use syringes sometimes ,no needle but a straw or pice of tubing .

[John Keeton]

DNA will thin the epoxy, but it also extends the cure time. It doesn't take much, so sneak up on it.

[Don Frank]

If your channel that the knife blade inserts into is perhaps 1" deep, drill a tiny hole at the back end of that hole. This will allow the air to escape when you inject the epoxy in. You can either thicken 5 min epoxy with milled fibers or buy some thixotropic epoxy. A jumbo syringe like you'd find at a farm store or a caulking tube that has been cleaned out will work as a delivery mechanism. If you buy a brand new tube of caulk, remove the cap on the back and clean the caulking out of the tube. Make sure it is clean and dry. Cut the tip off very close to the end so the opening is small. Dump your epoxy in the back of the tube, put the plastic plunger back in and point the tip straight up as you squeeze the handle. This will help you burp the air out of the tube until the epoxy is near the tip. This method will allow you to pump the thickened epoxy into the hole until you see it come out the pin hole. Then insert your handle and remove any excess that comes out.
This method works better if you have a large volume of work to do as there will be some wasted epoxy because it probably takes a couple table spoons to fill the tip of the caulking tube. It doesn't sound like your project will require much. If this method is overkill for your project, drill the tiny hole, pour in thinned epoxy and use a piece of straight wire chucked into your drill to coax the epoxy to the bottom of the hole. The turning wire will help to remove the bubbles and air pockets.

[Gerry Grzadzinski]

As mentioned, warm the epoxy, and warm the wood as well.
An alternative is to start with a thin epoxy, and add thickening fillers. This will give you a thicker epoxy that will still run into the hole.
I use US Composites, which is fairly inexpensive. I always keep a 1/2 gallon of resin on hand, with an assortment of fillers for different applications.

[Prashun Patel]

Thank you all for the tips, and Don, your last name is not Frank, it is MacGyver.

Al, it would be false bravado if I said yes...

John, I was counselled against using DNA or acetone to thin epoxy as it weakens it. Do you find this to be a non-issue in practice? For cosmetic cracks in barrel, maybe, but how will it hold up against a chunk of cracker barrel?? ;)

Gerry, I am tempted to buy larger quantities of epoxy because I can always use it. But I find more than a 1/2 pt goes crystally in the package. What do you do to keep it stable?

Brian, I am going to try what your and my instinct says...

[Dick Strauss]

To add to John's comment...1:1 epoxy to DNA will make it thin as milk and good as a finish but not much else. Add a few drops at a time until you get the consistency you want. When used judiciously, DNA worked better to thin epoxy (and maintained better than 75% of maximum strength) than any other solvent we tried in our experiments. YMMV.

Heat causes epoxy to cure too fast for most of my uses.

Epoxy components often can be heated in hot water in the bottle to reverse the crystal formation just like honey.

[Gerry Grzadzinski]

Gerry, I am tempted to buy larger quantities of epoxy because I can always use it. But I find more than a 1/2 pt goes crystally in the package. What do you do to keep it stable?


Nothing. I keep it in the garage, where it gets down to 30° or so in the winter, with no problems. I've had no issues with it, and have had some for 2+ years. Never seen the crystal issue in my 1/2 gallon jugs.

According to West System, if you warm the crystallized resin to 125° and stir it up, the crystals will dissolve.

[Don Nicholas]

I am making some cheese and butter knives.
I am having trouble getting epoxy (System Three T88) into the handle hole.

I prefer to use epoxy because the hole is round while the tang is a thin blade; so I have to use a gap-filling adhesive.

Do you have any recommendations for how to get thick epoxy into the hole, or a good thin-viscosity adhesive that would be appropriate?

It's a standard Craft Supply blade, and comes with a ferrule. Honestly, I think the ferrule looks cheesy ;), and would prefer to route out a thin mortise in two halves and then glue them together, but am unsure if this would be stable.

Any advice???
Prashun:
I use the same items from Craft Supply and use Stick Fast epoxy from the same vendor. I find Stick Fast is thinner than most brands. I drill the blade end with a drill that will allow the tang to enter the blank, then mix the epoxy with a tooth
pick (only use enough epoxy for 1 item at a time) then fill the drilled hole with epoxy using a toothpick to put epoxy in the blank, while filling the hole, wipe a small amount of epoxy where the ferrule goes and then push the blade in. The stick Fast seems to set up quicker than other brands.
hope this helps. I use this way for other of their kitchen items.

[Allan Speers]

Warming it before mixing sometimes thins it . I use syringes sometimes ,no needle but a straw or pice of tubing .


This. I've tried thinners in the past, but they are not recommended as they impede strength. In your case, that might not matter, so you could try acetone or MEK.

- but heat is generally better. I recommend heating the work, not the epoxy, so you have a little more working time.

[Prashun Patel]

Thanks Alan and Don. Every one of the posts on this thread was informative for me.

I love SMC.

[Reed Gray]

I do use the 2 part/tube 30 minute epoxies from the big box store. I found a syringe (opening 3/4 inch maybe, used for getting glue under the paper) in the wall paper department that takes about half of one of the epoxy things. Squirt it in, stir with a bamboo shiskabob skewer, and squirt into the holes. I toss them after getting done, but have enough pieces ready to use the whole epoxy mix.

robo hippy

[Kyle Iwamoto]

To get a thin blade in a round hole, I use a dowel a bit smaller, rip it in half and wedge it in with the blade. You'll have to do some planing and or sanding to get a good friction fit. Just put the epoxy on the 1/2 dowels and pound them in with a mallet. If you use a contrasting color wood, it adds a bit to the knife too..... Problem is you'll probably never get the knife blade back out, since it's held in by lots of friction and the epoxy.

[Curt Harms]

Nothing. I keep it in the garage, where it gets down to 30° or so in the winter, with no problems. I've had no issues with it, and have had some for 2+ years. Never seen the crystal issue in my 1/2 gallon jugs.

According to West System, if you warm the crystallized resin to 125° and stir it up, the crystals will dissolve.

Boy I wish I'd seen this a few weeks ago. I recently tossed a 3/4 full bottle of system three 5 min. resin because it had crystallized. I tried warming the same stuff to make it less viscous. It worked but the pot life was reduced to about 1 min. T88 is really slow set so warming it might work while maintaining reasonable pot life.

[Wayne Lomman]

Prashun, if you need to thin epoxy, you can do it using epoxy thinner, as opposed to acetone etc. In other words, there are as many types of thinner as there are types of resins so you would need to use the matching solvent. Adding epoxy thinner will slow the cure time but won't weaken the epoxy. Incorrect solvent will weaken it. Epoxy thinner will be available from any decent paint distributor who sells industrial coatings as part of their range. Cheers

[Prashun Patel]

Thanks for the tips, guys. Here's a brie knife.

[Gerry Grzadzinski]

Prashun, if you need to thin epoxy, you can do it using epoxy thinner, as opposed to acetone etc. In other words, there are as many types of thinner as there are types of resins so you would need to use the matching solvent. Adding epoxy thinner will slow the cure time but won't weaken the epoxy. Incorrect solvent will weaken it. Epoxy thinner will be available from any decent paint distributor who sells industrial coatings as part of their range. Cheers

Check the contents of these thinners and with the epoxy manufacturer. I just looked at two epoxy thinners that I found through Google, and they were basically a mixture of common chemicals that most epoxy manufacturers don't recommend using as thinners.

[Wade Holloway]

I have made knives for years. I use Devon 15 ton epoxy on most all of them. It sets up pretty quick and cures overnight. Once it sets it is easily cleaned up of any over fill. On these types of knives I would not worry to much and make it to complicated. Fill the hole to about 3/4 full using a tooth pick or a small piece of a wood dowel, then insert the tang of the blade and let it set up. If you put the epoxy in the hole on one side and let it run down it will settle without any air bubbles. You don't have to be in any real hurry it is not like it is going to set up in just a minute or two. Like I said I have done it this way for years with no problems. Good luck with your projects.

[Geoff Whaling]

Talk to a specialist epoxy manufacturer who sells epoxies into the construction & marine industries. They have a range of epoxy systems that will cover almost any application you can think of.

In Australia we have ATL Composites that sells an adhesive resin product called "Techniglue R60" and the hardner H60F - fast 15 min pot life, 8 hour cure; or H60S - slow 30 min pot life, 12 hour cure. It is a 2 parts resin to 1 part hardner ratio. The technical guide says water cleanup but I much prefer ethanol (metho).

"R60 is available with a choice of hardener speeds, and the thixotropic nature of the adhesive provides good gap-filling and hold-up on vertical surfaces."

The down side - it is only available in 500ml resin and 250 ml hardner minimum size, but the good news it is cheap compared to products such as Sellys 24 hr Araldite, and even better news because of the products thixotropic properties a little bit goes a very long way compared to Araldite when glueing in pen tubes. I purchase the R60/H60 through a local marine chandlery and also purchase two 25cc syringes to use to dispense the appropriate volumes and as a means to decant the small volumes that I use regularly. Smaller 5 or 10cc syringes can also be used to apply / dispense mixed adhesive into the sockets for knifes etc. They are used to boaties and wood workers purchasing syringes without needles.

I have found that 6cc's of R60/H60 will easily do 22 Sierra pen tubes in well formed 27/64" pen blank holes, where Araldite required almost twice that volume for 12 - 15 pen tubes because of it higher viscosity. In the tropics the R60/H60 lasts for many years as we don't have freezing cycles like you guys get.

One tip for knives a7 cutlery - use a 5cc syringe with a short acrylic tube extension to apply the glue. Prime the syringe / tube as all the best doctors & nurses do in the movies, feed the tube into the socket, then squeeze the glue into the socket with the syringe. Totally fill the socket from the bottom up - no air pockes or voids in the glue - and you get to see just how much glue went into the socket. cleanup is easy if you have applied sanding sealer to the item first or it is finished with a nitro cellulose finish.