T-Molding Help Needed

[DetroitKP]

I purchased 3/4" t-molding.  The depiction shows the splines to be 3/32" wide and the company recommends a 1/16" slot cutting bit.  I used a 1/16" bit and cut a sample slot in a 8" long piece of wood.  I then cut a 4" piece of the t-molding to see how it fit.  I could push the molding fully in the slot with my hand, and it seems to sit snug, but I can fairly easily pull it out (it wouldn't fall out on its own).  In all of the videos I've seen, people use a rubber mallet to pound in the molding (and I've seen it destroy wood when pulled out).  When I pull the t-molding out of the slot (I'm using hardwood, not partical board or MDF), it doesn't impact the wood.  Thoughts?  Think it is easily going in and out based on the fact that the piece of t-molding is only 4" long .... and it will seat much better when it is a longer piece?  Need some help.  Thanks!

[J_K_M_A_N]

The first time I cut mine, it did seem loose. I am not sure if I went the wrong direction with the router or if I had a small wobble but make sure you go in the right direction and keep it flat to the board. Myabe try another test piece. I did a couple and it ended up being nice and tight. Worst case, add some electrical tape or something to the t-molding to tighten it up.

J_K_M_A_N

[MartyKong]

Mine went in plywood as well. Fit pretty snugly and I needed a rubber mallet to install. Any chance you didn't router the groove cleanly? I think I purchased my T molding from GGG and had no problems.

[lilshawn]

i have noticed discrepancies in spine width as of late. The stuff I was using would shred wood upon being pulled out.  it had a fairly narrow spine and I had to purchase a special bit for it to fit properly.

as of a few months ago, the last 2 rolls i bought the spines have fattened out and i've had to change my bit to get it installed properly. the supplier must have changed makers or something.

old bit i used was 0.08in (2mm) new tmolding is now using a 0.13in (3.4mm) it's a little looser than I'd like so i could probably stand to go down to maybe 0.12in (3mm). the new tmoulding spine inclusive of barbs and everything is 0.14in (3.6mm)

i would measure the moulding spine, subtract 2 hundreths  (little more than half a mm) and buy a bit that width.

TL;DR - what bit you use is going to heavily depend on who manufactured the moulding.

[DetroitKP]

Thanks for everyone's feedback.  I'll use some calipers and measure the blade and splines.  I'll also check the angle to make sure it's perfectly parallel.  If all else fails, I'll use the tape method.