I've had varied experience filleting my LPR models. Initially I used Titebond No Run/No Drip (previously Titebond Molding and Trim), now I have a bottle of Titebond Quick and Thick, which is basically the same stuff, with one key difference. After doing a bunch of fillets last night, I thought I'd jot down my thoughts this morning while it's still fresh in my mind.
In general, this stuff is great, but there are definitely caveats, and specific techniques to use to get best results.
As mentioned, I started 3 years ago with this stuff:
I ditched the original nozzle (same as the normal TBII nozzle) and put on my own Elmer's cap to allow for more precise application. More on this in a moment.
Now I'm using this, shown here for some reason without the cap:
Again, this seems to be the exact same glue. However, note that the nozzle is new. Instead of the standard TBII nozzle with a pop-up tip, this one is just a hollow piece of plastic with a slit in the end, and a separate little white cap piece to seal it for storage. Here's the business end:
I've decided that this is a significant improvement. The consistency of this glue is very thick, almost marshmallow-y (especially as it ages). It benefits greatly from having an unimpeded path out the nozzle. That fine nozzle on my old bottle was a total failure. It worked initially, but has a strong tendency to clog up, and cleaning it is a pain. Thus far the new nozzle has stayed open and functional. Furthermore, although the slot is pretty wide, the glue flows slowly enough that I've found I can generate pretty consistent and fine beads once I get in the swing of things.
If necessary, you can simply tape over part of the nozzle to make it smaller and reduce the flow. I haven't needed to so far. Something sort of like this (shown on my TBII bottle).
To state the obvious: keep the nozzle clean. Wipe off any gunk before using it. Normally the little white cap will keep the slot open, but always check before starting.
Now, to actually make fillets.
The advantage of this glue is that it doesn't flow, so you can do all your fillets at once. Wherever you put it it's going to stay put. However, like regular TBII it does shrink a *lot*. You're not easily going to get epoxy-like fillets with this stuff, unless you're willing to do a lot of layers. Normally for LPR I don't care, but have realistic expectations.
The key to actually laying the fillets is to dispense the correct amount of glue. Much like making pancakes, I find that the first one I do in a session is not great; by the second (or maybe even third) fillet I've got the feel and get perfect beads. There is also the possibility of some slightly dried or thickened bits of glue hanging around near the nozzle, which will interfere with the flow. So squeezing out some glue onto a paper towel first is is a good idea, so that you can verify the glue is flowing smoothly through the nozzle.
Ideally you want to put in just *slightly* more than the exact correct amount of glue. Too much excess with this stuff really makes a mess. Don't squeeze too hard and keep the bottle moving steadily. Don't worry if you have a small gap in the glue here or there. Keep moving. And typically you don't need to go all the way to the end. Here was a short but really good one I did last night:
Nice and steady, just a bit of gap at each end. When I pull from the middle to the end, the excess on my finger will fill the ends. If it doesn't, I'll just apply a tiny dab at the end and pull it smooth.
Before pulling the fillet, dip your finger in water and then blot the excess. Using a wet finger is mandatory. Pull from the middle to each end, and don't press too hard. If you've laid in the correct amount of glue, you'll only pull a little bit of extra off on your finger. Further, you won't have large spreads of glue working their way up the sides of the fin and the body tube. That means you either put on too much glue or pushed too hard with your finger.
Then clean off your finger. Seriously. Wipe off the glue, then wet it again. This stuff is *sticky* having excess glue on your finger will create a mess on your rocket. DON'T SKIMP ON THIS STEP.
If the fillet didn't come out perfectly smooth, you can pull it again if you work quickly and have your finger sufficiently clean and damp. Just do the same thing again. After two pulls it should look good. Here's a 12" fillet that I really nailed last night.
Sometimes, despite my best efforts, I do push extra glue up on to the fin and BT. When the fillet is done, I immediately run a clean wet finger (or maybe even a damp paper towel) over the excess to remove it. Don't work too close to the fillet or you will risk messing it up.
After the glue is dry, it is almost perfectly clear. This can make it hard to tell how good the fillet is. Sight down it from the end to see it there are any gaps. I usually do a second layer on all my fillets, and at that point everything is good.
Once in a while a little lump in the glue finds its way into a fillet, interrupting the beautiful smoothness:
Usually this will mostly disappear when dry. But it's another reminder to keep the nozzle clean, so bits like this won't collect in there.
So that's it. To summarize the most important points:
1) Keep the nozzle clean.
2) Make sure the flow is good and steady before you start on the rocket. Squeeze out extra onto a paper towel before you start.
3) Don't apply too much glue into the fillet. Try to get an even bead.
4) Always pull from the middle towards the ends, especially on longer fillets.
5) Keep your fingers damp and *clean* (I can't emphasize this enough)
6) Don't be surprised when your beautiful wet fillet turns clear shrinks down into near invisibility when dry. It's still there and doing its job.
I hope this helps someone. This glue is great but it's easy to make a mess of it if you're rushing or not paying attention to what you're doing.
In general, this stuff is great, but there are definitely caveats, and specific techniques to use to get best results.
As mentioned, I started 3 years ago with this stuff:
I ditched the original nozzle (same as the normal TBII nozzle) and put on my own Elmer's cap to allow for more precise application. More on this in a moment.
Now I'm using this, shown here for some reason without the cap:
Again, this seems to be the exact same glue. However, note that the nozzle is new. Instead of the standard TBII nozzle with a pop-up tip, this one is just a hollow piece of plastic with a slit in the end, and a separate little white cap piece to seal it for storage. Here's the business end:
I've decided that this is a significant improvement. The consistency of this glue is very thick, almost marshmallow-y (especially as it ages). It benefits greatly from having an unimpeded path out the nozzle. That fine nozzle on my old bottle was a total failure. It worked initially, but has a strong tendency to clog up, and cleaning it is a pain. Thus far the new nozzle has stayed open and functional. Furthermore, although the slot is pretty wide, the glue flows slowly enough that I've found I can generate pretty consistent and fine beads once I get in the swing of things.
If necessary, you can simply tape over part of the nozzle to make it smaller and reduce the flow. I haven't needed to so far. Something sort of like this (shown on my TBII bottle).
To state the obvious: keep the nozzle clean. Wipe off any gunk before using it. Normally the little white cap will keep the slot open, but always check before starting.
Now, to actually make fillets.
The advantage of this glue is that it doesn't flow, so you can do all your fillets at once. Wherever you put it it's going to stay put. However, like regular TBII it does shrink a *lot*. You're not easily going to get epoxy-like fillets with this stuff, unless you're willing to do a lot of layers. Normally for LPR I don't care, but have realistic expectations.
The key to actually laying the fillets is to dispense the correct amount of glue. Much like making pancakes, I find that the first one I do in a session is not great; by the second (or maybe even third) fillet I've got the feel and get perfect beads. There is also the possibility of some slightly dried or thickened bits of glue hanging around near the nozzle, which will interfere with the flow. So squeezing out some glue onto a paper towel first is is a good idea, so that you can verify the glue is flowing smoothly through the nozzle.
Ideally you want to put in just *slightly* more than the exact correct amount of glue. Too much excess with this stuff really makes a mess. Don't squeeze too hard and keep the bottle moving steadily. Don't worry if you have a small gap in the glue here or there. Keep moving. And typically you don't need to go all the way to the end. Here was a short but really good one I did last night:
Nice and steady, just a bit of gap at each end. When I pull from the middle to the end, the excess on my finger will fill the ends. If it doesn't, I'll just apply a tiny dab at the end and pull it smooth.
Before pulling the fillet, dip your finger in water and then blot the excess. Using a wet finger is mandatory. Pull from the middle to each end, and don't press too hard. If you've laid in the correct amount of glue, you'll only pull a little bit of extra off on your finger. Further, you won't have large spreads of glue working their way up the sides of the fin and the body tube. That means you either put on too much glue or pushed too hard with your finger.
Then clean off your finger. Seriously. Wipe off the glue, then wet it again. This stuff is *sticky* having excess glue on your finger will create a mess on your rocket. DON'T SKIMP ON THIS STEP.
If the fillet didn't come out perfectly smooth, you can pull it again if you work quickly and have your finger sufficiently clean and damp. Just do the same thing again. After two pulls it should look good. Here's a 12" fillet that I really nailed last night.
Sometimes, despite my best efforts, I do push extra glue up on to the fin and BT. When the fillet is done, I immediately run a clean wet finger (or maybe even a damp paper towel) over the excess to remove it. Don't work too close to the fillet or you will risk messing it up.
After the glue is dry, it is almost perfectly clear. This can make it hard to tell how good the fillet is. Sight down it from the end to see it there are any gaps. I usually do a second layer on all my fillets, and at that point everything is good.
Once in a while a little lump in the glue finds its way into a fillet, interrupting the beautiful smoothness:
Usually this will mostly disappear when dry. But it's another reminder to keep the nozzle clean, so bits like this won't collect in there.
So that's it. To summarize the most important points:
1) Keep the nozzle clean.
2) Make sure the flow is good and steady before you start on the rocket. Squeeze out extra onto a paper towel before you start.
3) Don't apply too much glue into the fillet. Try to get an even bead.
4) Always pull from the middle towards the ends, especially on longer fillets.
5) Keep your fingers damp and *clean* (I can't emphasize this enough)
6) Don't be surprised when your beautiful wet fillet turns clear shrinks down into near invisibility when dry. It's still there and doing its job.
I hope this helps someone. This glue is great but it's easy to make a mess of it if you're rushing or not paying attention to what you're doing.
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