Tubasti glue...also known as elephant snot, is a thick and tenacious white glue. It works well but can be messy if you are not careful in its application.

If you are regluing previously glued rims you need to evaluate whether your rims need to be cleaned or can be reglued. It is ok to reglue if you are using the same type of glue and the glue residue on the rims is clean and fairly even coated.

If the glue is dirty, you are using a different type of glue, or not applied evenly you should consider cleaning the old glue off and starting fresh.

To clean the old glue off of aluminum rims I recommend acetone as it is available and highly effective. I do not know if acetone is safe for carbon fiber rims but others may chime in with a recommendation for carbon.

For gluing the tubulars...the tubasti directions are kind of scant but if you tried to apply the method from the first option you list you may find that to be too much glue. In any case, I would recommend 2-3 thin layers evenly spread on the rim allowing the glue to setup for a number of hours between coats. Then 2 thin, evenly spread layers on the tire as well. I apply the tire soon after applying the last layer on the rim so that the wet glue allows the tire to slide into place easily. This also will give you a short window to adjust the position of the tire so that it is centered all the way around. After it is centered pump it up hard and then wait 24hrs for the glue to set and cure for maximum bond.

If you are regluing previously glued rims then use a layer of fresh glue to reconstitute the old glue and then apply the glued tire as recommended above.

I like to use continental and vitoria glues as I find them easier to work with and get an thinner and more even spread.

I put a plastic bag over my hand and put a dab of glue between the spoke holes on the rim and then use a bag covered finger to spread the glue evenly on the rim between the spoke holes. Do one section at a time. It helps to mount the rim in a truing stand or in the frame suspended off the floor so you can rotate the wheel without it touching the floor or other potential vectors that may contaminate the glue.

Be sure to put a layer of glue on any spares you intend to carry as you dont glue spares on the road.

Also, stretch your tire by putting mounting it on the rim and pumping it up hard and then leave it for a few days. This will make the tire easier to mount once you have applied the glue.

Good luck.

-j