The 900 series tips supposedly will fit, but the new T-18 tips are specified for that model. They are fairly pricey @ $5-$10 each. There are some posts over at EEV that have users saying a 900 will fit on the 888, but it is not “snug” and perhaps could result in a looser fit and thus, a cooler temp. There are also some product catalogs which describe the T-18 as an “updated” 900 series tip. Going totally off brand with generic tips can be really hit or miss.
As cheap as generics are, I would sure try some to find a few that would fit.
I would also consider getting a square of cement rock or other robust inflammable substrate for a firm base for high temp work. I have also seen a high temp silicone baking mat used. Some people also utilize a jig to hold components securely.
My .02 worth? Allis Tissue Forceps for clamping onto small objects, like holding extra 7135 chips to a driver, for soldering, or for holding any small parts, even for soldering while clamping. Ebay search link here.
I use 60/40 rosin core solder. It's because it melts at a fairly low temp and because it flows well. I also use a container of rosin flux and a tiny paint brush, like the ones for paint by number kits. I flux everything I solder. Flux makes the solder flow so easily. If you don't like the flux residue, you can clean it up with alcohol.
I did scrapped the aluminum pill with a knife and didn’t seem to help. But I have never had that good of a bond with anything else when soldering to aluminum either. I thought the goot flux might help, aluminum is just a stubborn alloy to solder to.
Strange I have used the FT solder myself with no real problem. Did have a batch which were a bit light on flux though. When I started most solders weren’t multi-core so I tend to use separate flux a lot, could be the reason.
But I agree named good quality solder makes life easier and better.
I Puddle the flux then scrape the alu’ under the puddle so the air does not get at the alu’, then puddle the solder and scrape under the molten solder, a sharp chisel tip helps. As Chloe says spits and nasty fumes.