I'll first say that Im sorry for how long this reply will be. Secondly, I am not an expert, I just know what works for me in my process. Before Gluboost was offered in our penmaking and woodworking world, it was specifically used in the guitar building and repair world. Mark Dreyer was the first to use it, and the owner of Gluboost, Rick Rosenberg, was looking for another to give an opinion, so Mark introduced me. Since then, Mark and I have been asked to use other products in production before they were brought to market to give honest opinions so the products could be "tweaked" for woodturning needs. I can honestly say I put that stuff to the test, evaluating it as an adhesive, finish, stabilizer and scratch remover. The best part about Gluboost is there is no "one way" that it has to be applied. Mark and I do it differently and both get great results. Before I get too deep in answering what I can, I just want to say, I don't work for Gluboost and I don't receive any payment for demoing or showing how I use it. I only endorse it because I feel it is the best CA finish I've ever worked with.
As far as I know, there is no issue of strength between the Gluboost straight CA and the fill and finish line. I've used it as an adhesive and a finish. When gluing something together, like a broken blank, I apply GluDry to one half and Gluboost to the other. You have a couple seconds to get it in position before it begins to set. I've also used it to fix router tear outs on end grain with great results.
Like many of you, I stared out using and trying all the brands.... Starbond, Satellite, Mercury, EZ Bond... (off the top of my head). In those days it started out with CA and BLO (boiled linseed oil) applied together. The problem I seen was with use the shiny finish dulled, but it was easier to apply than just a straight CA finish. Then BLO was left out and CA was applied very thick and sanded down smooth to a finish, much like my process now, only with less CA applied and other steps applied. There is a learning curve to a CA finish. You have to pay attention to lathe speed, glue amount, how you fold your paper towel, how quickly you move across the blank, how much pressure you apply, etc.... Your Process.
I use all of the Fill N Finish products.... the Ultra Thin (teal label) Thin (orange label) and Medium (blue label) for my finishes. I first practiced on wood.. smooth wood, oily wood, porous wood, hard wood, soft wood, etc... I learned you don't have to use all of the Gluboost thicknesses on every blank. Smooth woods I only use the thin (orange label). For open pours or holes I apply a few layers of the medium (blue label). Now that we have "Ultra Thin" (teal label) I start every wood blank off with at least 2 layers of that. It soaks in, fills grain and sanding scratches, and builds a nice base for what I use next. The beauty of this product is there is no set process. For me, the blank dictates what I need to use when.
Ultra Thin - for scratch sealers on acrylics, base coat on wood, stabilizer in soft woods and embedded object casts, and fine cracks filler.
Thin - finish over smooth woods and acrylics.
Medium - fills pour, voids or tare outs, levels wavy surface or out of round blank, builds up over turned blanks, and works great with
master tints for coloring blank.
As for the accelerator, in past brands I would omit use and wait 30 minutes between coats, trying to avoid any crust or bubbling up. With Gluboost, the accelerator is recommended to get the proper cure. You're building layers so you want each layer to properly cure before adding the next so you don't trap uncured CA under your finish. I apply my CA and accelerator with the lathe on very low, around 600 rpms.
I take a 1/4 sheet of Bounty paper towel and roll it up like a long tube. Then I flatten it so its about 1/2" wide. I start at the tip with glue and work my way back down the towel as I go. I place about a 1/4" circle of glue on the towel and wipe it across the blank. If I'm using medium as a filler or leveling out a surface I stop the lathe for a few seconds to allow it to self level, before turning the lathe back on and apply the GluDry. If I'm filling a void or hole, I apply it with the lathe off so I can get it where I need it. I don't fill the entire hole in one shot, I apply a few layers so it cures properly. When I apply the GluDry, I hold the can out about 10" from the blank and give a 1-2 second burst. I don't need to paint the surface, just get it to mist across the turning blank. Until you get familiar with your process, I would suggest you stop the lathe to make sure the surface is cured before adding the next layer. By lightly spraying the accelerator your curing that layer and now the next layer will cure from both sides... the bottom of the layer and the top after you spray it again. This ensures I have a fully cured finish and not something with a bubble or blister or CA trapped. I kept count on how many pens I could make with one can of GluDry last year by marking the can every time I finished a pen. I made 52 with one can. I applied 4-5 layers of Gluboost per pen then lightly sanded with 600 grit, followed by #0000 extra fine steel wool across the blank with the lathe on high. That seems to smooth the glue out without leaving hard scratches. Then I wet sand with all 9 grits of Micro Mesh, followed by micro fine Yorkshire Grit on a cotton t-shirt with the lathe on high. Buffing is only as needed after that. Some blanks may have slight blemishes that I want to buff out on the Beal Buffing System. Obviously the blank with dictate how many layers of glue and what thickness I'll use. Most of my GluBoost finishes take about 5-15 minutes from start to finish. Just because it worked quickly on one blank doesn't mean it will be that fast on all of them, but my longest finish with Gluboost was still much faster than with any other brand I've used and I've never had a Gluboost finish crack later like I have with all of the other brands. The shine has always held up with use and quickly polished with a rag or shirt if finger prints dull it down. I've read others mention that they don't apply a CA finish over resin blanks. I have found a huge difference between those with and without it. The only resin I don't use it on it Polyester (my feather and snake blanks). That resin is harder than cured CA and finishes to a high shine naturally. Epoxy and Urethane resins are softer and will dull with use. Plus it takes longer to get a shine on these resins with out CA than by just applying a CA finish. It also enhances the colors in a resin cast. I've shown that example on here before by applying GluBoost to half the color cast and finishing the entire blank the same. Colors are more bold/deep/rich with GluBoost over it and the shine will last with normal use because the CA finish is harder than the resin.
As for casting.... I don't care was brand it is, No CA works with Urethan resins. It will work with Polyester resins as long as it's not too deep, but you have to let it degas for a couple days so it doesn't make the clear resin cloudy. I've used Gluboost (green label- thin adhesive) for building blanks to cast but only where the glue is under something and not on the surface to be seen, like snakeskins and such. I know some like to use CA on watch part blanks but I much more prefer clear nail polish for that. It's thin enough to not be seen and dries quick, and it works well with all resins but it needs to be fresh and not super thick.
I like to have an extra bottle of CA on hand. That gives me time to order a bottle when needed without holding me up if I run out, so I'll order a replacement when I'm about half full on the bottle I'm using. I store the unopened bottle in the shop refrigerator. Once it's open, don't put it back in there ( straight from the manufacturer). I always write the date on the bottle with a sharpie when I get it. I've had bottles that started in the fridge before being opened that took over a year before I used it all up, with no problems. Sometimes life gets in the way and I don't make as many pens for a while and the opened CA sits on the shelf above the lathe. I've noticed some get a little thicker but I've never thrown a hardened bottle away before I used it all up, like I have with other brands. I cap the bottle when I'm done for the day but I know others who don't with no issues. My shop is in the basement so it stays cooler year round. I don't know if GluBoost in a hot shop would have the same results.
I've had others ask when to use what with Gluboost and give the best advice I can but the best thing you can do is get a bottle of each Fill N Finish (teal, orange and blue label) and use them. If I had to pick, I would choose (teal label) Ultra Thin and (orange label) Thin. I think you can achieve all of your needs with them but you will have to apply more layers to equal what the blue label Medium does.
I posted links to some videos on how Mark, Ed and I use Gluboost, for anyone who has questions. You can see how we each do it differently and over different materials, but get great results. There are more on each channel you can scroll through and watch but these will get you started. Hopefully it will help some come up with a process that works for them.
My process...
Mark Dreyers process...
Ed Brown's process at Exotic Blanks
I hope this helps and I apologize if I left anything out.