GluBoost - Optimizing Your Finish

[jrista]

I finally took the plunge into GluBoost, as my Pens Plus bottle (at over half full, as it seems) has gone bad. Given the amount of waste I've had with Pens Plus, despite the fact that I like it as a finish, and love that there are zero health implications with it, I'm giving GluBoost a try. So far, I LOVE the look of the finish when its done. It looks better than other CA finishes, doesn't really have that plastic look. It may not be as durable, I'm not sure. I've had some trouble with application, though, which may be environmental (humidity and/or temperature related). I've also not quite been able to get the finish to be as efficient as I'd like it to be.

In my other thread on GB, I noted that some other people have had some troubles with this finish as well...so I thought I would start a thread where people could share their tips, tricks and application ideas to everyone.

GluBoost Basics

• This is a CA finish that relies on an accelerator to cure properly: GluDry.
• Its ideal working humidity range is < 70%; >= 70 < 75% it is going to be problematic; >= 75% you should wait till humidity drops
• Optimal humidity seems to be quite low, at least in my experience, and I've had longest open time around 20-25%
• It seems to have an optimal working temperature of around room temp; Over about 72 degrees it seems to gum up more easily
• It seems to have a sensitivity to lathe RPM, and will apply most optimally at around 400-600rpm
• The thicker stuff is the BLUE bottle
• The thinner stuff is the ORANGE bottle

GluBoost Application

APPROACH #1

Put finish on applicator, apply to blank. This can potentially allow for more efficient use of the finish. As GluBoost is rather expensive at $15 a bottle. If you use both the thicker and thin stuff, then that's a $30 outlay for the finish itself, plus the cost of GluDry. So keeping the coats thinner, and ensuring as much finish gets on the blank rather than staying in the applicator is key to that efficiency. This particular approach, at least in my experience, seems prone to rapidly thickening glue, which gets sticky and gummy and has shorter open time for spreading and optimizing the appearance of each coat of finish.

• A "craft foam" applicator seems to be the best option, as it balances out rigidity and flexibility to ensure the finish fully coats the blank
  • Foam applicator also generally ensures that the finish gets on the blank, rather than soaking into the applicator
• If you find you get a white crystalline-like "frost" on your blank with a foam applicator, it may well be the foam itself, or something on the foam
  • TIP: use a spray adhesive to coat a sheet of the foam, and apply a sheet of was paper to it
  • The was paper will neither react with the glue, nor stick to the blank
• A popsicle stick with wax paper can also serve as an applicator in a pinch, although being rigid it can sometimes be harder to fully coat the blank
• Paper towel applicators can work as well, although they do absorb the CA, which will often react with the fibers and "burn off", not to mention waste some finish
  • Paper towel applicators, if you are struggling with issues with your GB finish, may be a part of the problem
  • Any dry part of the paper towel applicator that does not have GB on it can mess with the way the applicator applies, and can cause streaking and accelerate gumming up of the finish (particularly with the BLUE, ticker stuff
• Open time with GB may be very short, depending on your environment, applicator choice, wood (especially if its very dry and porous and you are on the first few coats)
  • Under optimal conditions, open time should be ~10 seconds or more
  • With a foam+wax paper applicator, under ok but not optimal conditions, I've had up to 8 seconds open time to spread the finish off the applicator
  • With paper towel, I rarely get more than a few seconds to apply before the finish starts to gum up and streak, leave globs behind, etc.
• Once you feel the first slight grab, remove the applicator from the blank
  • If you haven't fully coated, add more finish to applicator and complete coating of the blank

APPROACH #2

Put finish on blank, spread with applicator. If you have trouble with approach #1, then you can use this approach. Instead of applying finish to the applicator, you apply to the blank and spread the finish out with the applicator. This is most likely going to use more of the finish, possibly a lot more, as you are basically slathering the blank in finish. The use of a whip tail applicator, trimmed to the point where you get just the right flow rate of glue from the bottle onto the blank, can help improve efficiency here. It is a trial and error process. Application of GluDry with too much finish in each coat can result in "The Wrinkle", an unsughtly wrikled orange-peel like appearance to the finish (although this can also occur with approach #1 as well.)

• A "craft foam" applicator is a good option here, although it may not be the most optimal. See above for more details about this applicator.
  • If you are using a whip tail applicator with the GluBoost bottle, and have optimized your rate of flow ideally, this is probably the best applicator
• A popsicle stick applicator is less optimal here, especially if there is any kind of curvature to the blank. I generally avoid.
• A paper towel applicator in this case, folded over enough to be very narrow, may be beneficial as it can absorb some of the excess finish.
  • Good if you haven't optimized your glue flow...but, absorbing the excess finish does still mean you are wasting it.
  • Ideally, invest time in trying to optimize your glue flow if you can.

This approach is often the only way I am able to get a nice "crystal clear" coat of GluBoost on my blanks. Additionally, use of GlyDry, which is generally required, may result in an otherwise perfectly clear coat getting wrinkled instead. Not entirely sure why this happens but air drying will often leave you with a slightly rippled coat. The coats with this approach will usually be thicker, and if you build up enough, the finish may start to look a bit more plastic. Keeping the GB finish moderate in thickness seems to be an optimal balance between durability, and clarity. When the finish is super clear and free of any scratches, it does not take on that "plasticish" appearance IME.


Drying the Finish

This is where GluBoost seems to get a bit tricky, at least it has for me. Drying is not always ideal with GluBoost. When humidity is extremely low (20% or thereabouts), it may do better, but when humidity is high (> 50%) you may run into problems. When humidity is very high, you may get even more problems. Drying can be done with or without GluDry, however GlyDry is required according to the official documentation for how to properly apply this finish. GluDry can impose some potential side effects, though, so beware.

• CA dries (cures) by reacting with water which initiates a polymerization and cross-linking process
• Curing will generally crate a film like coating on the surface instantly, slowing the rest of the curing process
  • As such, thin layers cure well, thick layers not as well
  • This thin skin may be the reason a wrinkled surface appears when coats are dried with some glues
• Curing produces formaldehyde which is generally what you see when the glue is off-gassing
  • This can also be a component of irritation if you breathe any in, as it polymerizes arbitrarily, and is toxic
• Accelerators function by improving moisture aggregation on the surfaces to which it is applied
• If a blank is rotating, has airflow from a dust collector, and also has other airflow, this may accelerate and change the drying process, resulting in a less than optimal appearance to the final result
• A wrinkled, mottled, or frosted surface may lead to greater required effort in sanding to smooth out the finish surface, and final polishing to achieve a scratch-free result

TODO: ...

 

[montmill]

I'm curious if others have found that when Gluboost gets a little older it seems to look more "plasticky". I was having that issue but it resolved with a new fresh supply.

 

[JohnU]

I've never had any issues with Gluboost. I apply it like I have other brands only less layers because it levels off and doesn't crust up. I always sand a little after my last coat with 600 grit, to make sure I dont have any high spots. I always hit it with extra fine steel wool (with the lathe on high) before wet sanding with micromesh. I finish with polish and a little buffing and it looks like glass every time. The plus side is I don't have to wait forever between layers and it's flexible so it doesn't crack. I even apply it over my color casts because the pens shine longer after use.

 

[bugradx2]

I've found with my GluBoost experience that the less I mess with it the better off I am. I use a piece of paper towel that's rolled/folded up to apply mine. I'll put 3 or 4 drops of it on the paper towel and start in the middle of the blank (lathe running 500 or 600) and wipe across the blank a couple times and then hit it with GluDry. I'll do 3 or so coats of the medium and then 4 or so coats of the thin. They're all applied the same way. I go straight to micro mesh wet sanding from there. When I'm done the finish looks great. I have gotten in the habit of buffing with some Flitz on the lathe when done also.

I'm lucky that my shop is in our basement and is temp controlled, the basement is unfinished so the humidity moves a little more with the time of year but it's not bad. That may give me more consistent results than some of the other turners who have outside or garage based shops.

For the sake of honesty, my approach is based on what works for a buddy of mine and what I've seen John Underhill and Mark Dreyer do. I am closer to John's technique than Mark's though.

 

[jrista]

I've found with my GluBoost experience that the less I mess with it the better off I am. I use a piece of paper towel that's rolled/folded up to apply mine. I'll put 3 or 4 drops of it on the paper towel and start in the middle of the blank (lathe running 500 or 600) and wipe across the blank a couple times and then hit it with GluDry. I'll do 3 or so coats of the medium and then 4 or so coats of the thin. They're all applied the same way. I go straight to micro mesh wet sanding from there. When I'm done the finish looks great. I have gotten in the habit of buffing with some Flitz on the lathe when done also.

I'm lucky that my shop is in our basement and is temp controlled, the basement is unfinished so the humidity moves a little more with the time of year but it's not bad. That may give me more consistent results than some of the other turners who have outside or garage based shops.

For the sake of honesty, my approach is based on what works for a buddy of mine and what I've seen John Underhill and Mark Dreyer do. I am closer to John's technique than Mark's though.

I suspect the temperature controlled environment helps. My garage varies a lot, which has made it hard to tell why I can't just apply it simplistically.

I've tried the "just put it on some paper towel and run back and forth a few times", and it hasn't really ever worked for me...gums up before I can get the "back and forth a couple times" (let alone more). I am at high altitude...so, maybe its a combination of thinner air (~6000 feet above sea level), temperature (close to 80 or above most days during summer), and maybe humidity (been highish lately, at least for Colorado.)

 

[bugradx2]

I suspect the temperature controlled environment helps. My garage varies a lot, which has made it hard to tell why I can't just apply it simplistically.

I've tried the "just put it on some paper towel and run back and forth a few times", and it hasn't really ever worked for me...gums up before I can get the "back and forth a couple times" (let alone more). I am at high altitude...so, maybe its a combination of thinner air (~6000 feet above sea level), temperature (close to 80 or above most days during summer), and maybe humidity (been highish lately, at least for Colorado.)

I really wish I could help you figure it out but it's past my experience. John and Mark would be great resources, so would Ed. For that matter you could probably even ask GluBoost

 

[jrista]

I really wish I could help you figure it out but it's past my experience. John and Mark would be great resources, so would Ed. For that matter you could probably even ask GluBoost

I've asked them all at this point. GluBoost team says its humidity, but I have the same issues at 20% as I did over 70%. I've tried different application methods from Ed, John, Mark, and a few others. Different applicator types.

The only thing that really seems to have been fairly consistent, is temperature...its relatively highish (i.e. around 80, or above), but it hasn't been particularly hot (i.e. 95, 100 or more).

I've tried a bunch of different woods now. I seem to have the same issue no matter what I do. Only thing I haven't tried yet, is to apply it at say 60 degrees...dunno how that might go.