I’ve bought some new rims which are 25mm internal width (WTB I25 KOM) and last night used stans 25mm tape to seal them up. Trouble is the tape didn’t go right to the edge of the rim bead – therea a mm or two on each side. Is this going to present any problems when trying to get the tyre to hold air? Have since read that WTB recommend 28 or 30mm tape but am reluctant to buy more tape, undo it all and start again unless I have to.

as long as it covers the spoke holes it’s all shiney.

covers the holes and nice and tight (aim to break a sweat wrappin it) and you will be fine

Hair dryer/heat gun makes it nice and tight and sticks well.

sounds good to me, yeah my forearms were aching and my thumb was sore from pushing it into the central channel hence not really wanting to do it all again!

Try it. If it inflates, job done.

I like to stick a tube in and leave it inflated for a bit to properly press the tape down, but as long as it’s covering the spoke holes it’ll be fiiiiine.

Just cover the holes and make sure it’s stuck good and proper. Inflating it overnight wit a tube in will help, but any small leaks should be sealed by the sealant anyway…

I had the same issue with these rims. It sealed fine but when I removed the tyre, the bead caught the edge of the tape and lifted that off with the tyre. I ended up using wider tape and it works fine.