I'm a beginner starting my first fly rod build with low cost parts and my question is; my reel seat is an ATC AL8 that came with an aluminum tube, should a beginner build up the rod blank with masking tape to fit the reel seat tube or should I buy a reel seat insert and get some practice using a rat tail file to ream out the insert. I plan on building several more fly rods with better quality parts as a hobby, also is the masking tape technique with epoxy a good quality construction.

Using masking tape as an arbor is done all the time and works very well, especially if the gap to fill is not overly large. Leave gaps between the tape wraps for epoxy to adhere directly to the blank.

I also think it wise to totally encapsulate the masking tape to prevent any water that might get in from affecting the tape. As Phil says, masking tape is a fine "component" if properly used. Simply wrap it tightly, use your fingers to press it together to assure no gaps between layers, and totally encapsulate it. Will last forever.

If you use polyurethane foam cores split them up also at least in three parts (one each end and a middle piece) and encapsulate them with epoxy the same way you would with tape. Whatever you use you want to seal it to not let water get to it. Does anyone use those universal plastic / vinyl ones anymore?

I’m not mastered in any way, but I’ve used the foam arbors and Pro Paste. They worked well for me. Clearly masking tape works well...or nobody would recommend it. Sometimes the old ways are the best. However, I’d avoid any fast setting epoxy. You can get cheap epoxy with 20 minute working time from Harbor Freight. I use it all the time for butt caps, as well as having used it on the handle & reel seat of my first rod build. It’s perfectly fine. I’ve also taken the extra step of sanding the inside of a reel seat so that the epoxy or epoxy paste isn’t being adhered to a slick surface. Most reel seats have interior ridges that grap whatever adhesive is being used. If it doesn’t have those ridges, then sanding or scuffing will help. Most importantly, make sure you mask off the cork handle before you glue the reel seat up. That’ll save you a lot of aggravation from the messy expoxy which will squeeze out.,

-Raymond

For most reel seats I like using foam cores. However, when the gap to be filled is small I like to use dry wall tape. It is basically a very light fiber mesh, and the mesh allows the epoxy to percolate through it giving a very strong bond between the blank and the reel seat, or whatever else you are shimming. It is also very inexpensive.
Norm

I 2nd the dry wall tape, an will wind some thread around the tape to hold it in place [ not a lot] as it some times will not stay in place as I put the seat on,

William Sidney
AK

Bill is correct. Sometimes dry wall tape will walk on you when epoxy is applied. This problem can be solved by either tacking the leading edge of the tape to the blank with supper glue before wrapping it on, or, as Bill mentions, wrapping a little thread on top after wrapping the tape on the blank.
Norm

Make sure it's Mesh drywall tape. Not paper tape.

For rods where it doesn't work well to use foam arbors, I will use masking tape.

I use tape of various widths from 1/4 inch to 2 inch wide. I will wrap an arbor of the appropriate length, and then leave about a 1/16th inch space, so that epoxy can fill any gap between the strips of tape arbor.

I use narrower tape at each end of the arbor and wider tape in the middle. That way the tape is well sealed in epoxy and I will say that I have never had a reel seat come loose using this system.

Good luck