Printable View
Hi! I am working on the wooden ribs for my Baby Great Lakes project. The pieces are glues together with FPL-16A Hughes Glue which is an epoxy that mixes 10:1 by volume. Does anybody have any exerience with this type of epoxy? Any hints? Most important however, anybody have any suggestions/tips on how to mix small batches of epoxy in a 10:1 ratio? Thanks
You can get small graduated plastic cups (I get them at West Marine) for the resin and nyquil cups. West System also sells some nice plastic popsicle sticks which are round on one end and square on the other that are real handy for a number of reasons. For the actual mixing, I tend to use greek yogurt containers that my wife retains from her lunches, etc...
Forest Products Laboratory -16 glue has been around since the '60's. Good stuff for gluing wood together. I think they changed the formula slightly with -16A version to get rid of toxic components.
I woud just use non waxed paper cups like Dixie brand. Put 10 units in a cup, mark it with a sharpie and measure it with a ruler. Mark other cups based on that measurement. Same for the 1 unit cups. When mixing glue, pour the smaller volume into the larger. Wet out the cup before starting. That will give you plenty of accuracy and you can just pour directly into the cups. When you make small batches it's difficult to keep the ratio accurate so try to avoid 10 drops to 1 or something like that.
Does the product have a "mix by weight" ratio? I'm more comfortable with that and have a set of cheap balance beam scales to ratio epoxy. I believe that is a more reliable process for me than mixing by volume.Quote:
Originally Posted by Pacer90A
Go to your local farm store, they have syringes graduated in any amount you like.
For what its worth, your local auto paint store has clear plastic mixing cups that have ratios marked on them. Some paint is mixed 3:1 paint to hardener, some 6:1, etc. Its all printed on the side of the cup so you put paint in up to the 1 line, then add catalyst up to the next line, etc. As idiot proof as they can make it.
That said, using West System with the pumps that just provide the right ratios is about as easy as it gets.
Best of luck,
Wes
N78PS
I didn't like the West System pumps. Seems they get air in and it takes a few pumps to get a full shot.
Instead, I pour a line of resin on sheet of cardboard 5 inches long and a line of hardener 1 inch long next to it and mix it up.
(West System is 5 to 1)
Thanks for all the good advice. When you say "wet out the cups" what does that mean?Thanks again.
Wes,Quote:
Originally Posted by WLIU
We have had a lot of issues with the West pumps, mostly from a limiting collar on the resin pump that shifts. Since then we have gone to the measure by weight system. Just too risky using the pumps as you never know if it has dispensed correctly until its too late.
I built a small scale for weighing epoxy. It works just fine for 1:1 or 2:1 but it might need a little calibration for 16:1 use.
I started with a straight piece of wood about 1 x 1/4 x 18 inches. I cut a groove across the wood (in the center) and glued in a piece of wire to act as a pivot point (fulcrum?). Then I measured out points on either side of the pivot (on the other side) to reflect positions to place little waxed paper cups from the grocery store. Each point becomes a line drawn across the board. If you want 2:1 you place two cups - one on the left and the other on the right twice as far from the pivot point. Start with the material you need more of (resin?) and pour the amount you want in the cup closer to the pivot. Place the other cup on the position further along the board according to the ratio you want. Dribble in the material (hardener?) until the board moves from one side to the other. I do this on a piece of waxed paper on my bench, but I don't think I have ever had a spill of these small amounts of stuff.
This might not work as well for 16 to 1 because the weight of a single cup might be significant. Perhaps you can calibrate it by using known weight samples in sample cups (for example a single an-365 nut against 16 of the same size nut) to find the proper position for the cup nearly 16 times as far from the pivot.
I never reuse the cups. They are easy and cheap to replace at the grocery store. The kind I use are intended for bathroom drink cup dispensers.
It is absolutely CRITICAL that you use UN-Waxed cups. This was mentioned in another reply but I feel that it did not stress how critical that is. I have quite a bit of experience with different epoxies including FPL-16 and T88 in gluing wood. A friend came to me asking why his Tailwind rib joints were not staying together. The culprit was the WAXED bathroom cups he was mixing in. The epoxy picks up or absorbs the wax and as it cures, forms a very thin film on the wood surface. The Tailwind ribs could be disassembled with very little pressure. The joints came apart with virtually no fiber breakage of the wood. It would have been disasterous if the error had not been found at this early stage. He was sharp enough to realize he had a problem when he broke joints getting a rib out of the jig after a 24 hr cure!
Epoxy depends on a molecular link to properly cure and achieve the manufacturers design physicals. Therefore it is very important to get the ratio correct. (Polyesters depend on a catalyst action as opposed to the molecular link and are not as critical. A drop of hardener will cure a gallon of Bondo, although very slowly!)
I cannot find a reference for a ratio by weight for FPL-16. I like the suggestion of the syringes from the Farm Store and plan on checking them out. Good luck with your project!
Quote:
Originally Posted by Pacer90A
I think the easiest way BY FAR is to buy a cheap postal scale, set it to grams, and mix away. You can reuse plastic mixing cups that have hardened epoxy in them by zeroing out the cup each time before adding epoxy. Note that mix ratios are usually stated by volume, not by weight. Here's the way to convert very simply, if the viscosity of the materials are about the same, use the same ratio when weighing. If the hardener is thicker, use less hardener (the manufacturer can give exact ratios, sometime on the label or MSDS.Example: in the 3:1 epoxy I using right now (thick hardener) I pour resin in the cup first---always zero the scale when you place your container on it--if it turns out to be 75 grams, 25 grams of hardener added will work just fine but is actually too much because of the greater viscosity, I use about 22 in this case but if a little extra drips in, it is not an issue.