Hello everyone.

I've been installing 3/4" x 5" solid Sucupira with "nail & serpentine-glue-assist" throughout my home. In my living room, I would like to do a picture-frame pattern (or cabin floor as some call it). I plan to router all plank ends for tounge & groove connection.

So I have some questions for you guys & gals:

1 - Is it ok to use nail with glue assist for this pattern?
2 - Should I use "tounge & groove glue" in the end connections?
3 - Is it acceptable to groove all ends & use spline instead of cutting tounge to eliminate end=grain tearout while routering?

Thanks for any advice

You can continue using glue assist when making the log cabin or mitered border.
It will not be helpful to glue the T&G together at the corners.
You can use a router with the grooving bit to help keep the corners even. Use the bit oriented with the bottom of the flooring. Run the router along the bottom of the flooring instead of from the top. This way there will not be hollow spots if the flooring is not perfect thickness between boards..
I think that you will appreciate the border more if you do more than 3 rows. Traditionally an odd number of rows are used. If you are having fun, you can go all the way toward the center of the room. To finish, the field is started from both sides and you may have a rip, or two to make it so there will not be a toothpick width remaining or a taper to nothing at one end. Spit the difference if there is a little left that is more than one board width and make two boards that are close to even.

Thankyou. I'm actually doing 30" wide, or 6 planks border, with carpet in center. Kind of how it was before, but was 5/16 floating oak. There's also a fireplace set at 45 degree in corner.

Does it make any sense to groove only ends & use spline to avoid tear out?

You could use spline, but it is not necessary if you use glue along with fasteners.
Not just carpenters glue, use floor installation glue.

Thanks so much, I'm all set now.