Quick plastic/glue question?

[PWR RYD]

Does anyone know what type of plastic these ports are made of?

http://www.parts-express.com/pe/show...number=260-386

I'm asking because I need to glue them to a couple of plywood flanges and the label on the Gorilla Glue bottle says:

"Not recommended for use on polyethylene or polypropylene plastics".

If these ports aren't compatable with Gorilla Glue than any other glue suggestions that will provide a nice strong bond to a smooth, clean, plywood surface? Thanks!

[billfitzmaurice]

Probably ABS. Maybe polystyrene or PVC. Parts intended to be glued are almost never made of polypropylene or polyethylene as they're very difficult to glue, usually requiring plastic welding.

[Chris Roemer]

Does anyone know what type of plastic these ports are made of?

http://www.parts-express.com/pe/show...number=260-386

I'm asking because I need to glue them to a couple of plywood flanges and the label on the Gorilla Glue bottle says:

"Not recommended for use on polyethylene or polypropylene plastics".

If these ports aren't compatable with Gorilla Glue than any other glue suggestions that will provide a nice strong bond to a smooth, clean, plywood surface? Thanks!

You could try RTV silicone or 5 minute (2 part) epoxy, but I'd think even GG would stick well enough as long as you roughed up the glue area wth some coarse sandpaper (on the plastic).

Chris

[kornphlake]

Probably ABS. Maybe polystyrene or PVC. Parts intended to be glued are almost never made of polypropylene or polyethylene as they're very difficult to glue, usually requiring plastic welding.

These particular ports have holes for fasteners though, I don't have any reason to believe they are intended to be glued. Polypropylene and Polyethylene are most often the cheapest plastics when superior mechanical strength isn't needed. That said, plastics referred to as impact resistant are often a blend of ABS and Polycarbonate.

[jonpike]

Yep, the sandpaper is a good tip. I've had good luck gluing plastic with epoxy by roughing the surface, and insuring that it's clean. (no skin oils, etc) Wipe it down with alcohol, and let dry. Then epoxy will stick really well.

[PWR RYD]

Thanks for the help guys. I think I will pick up some two part epoxy. I'll post up some pictures in my build thread that will show what I'm doing. In a nut shell, If you cut a hole in your board and use the 4 mounting holes to secure it, you will never be able to remove the larger diameter sliding section of the port. Or if you cut the hole large enough for the sliding section to clear, there won't be more than a millimeter of wood left for the mounting screws. So I made much larger diameter plywood flanges that the ports will be glued to from the backside. This will allow me to give the front of the port a nice large radius as well as provide me another access point into the enclosure (baffle and back are not removable).

[arlis_1957@yahoo.com]

i have used the two-part epoxy for this. i like the fact that i can incorperate a roundover sand and paint it.

[LouC]

Silicone or hot melt would be worth trying. Those ports are ABS I believe, the press fit type (260-478) a Polyethylene base (like a typical milk jug)

For the most part, if the plastic has any flex to it, or feels a bit "greasy" to the touch, it's not likely to glue well.

[PWR RYD]

Thanks again for the info. The glue in this situation won't need a whole lot of strength because the ports themselves virtually weigh nothing and there will be no (hopefully) real stress working on them. The only real stress they will see is when I use my router with a flush trim bit to match the size of the plywood flange hole to their inside diameter, then the load of the bearing of the roundover bit that does the "flare" in the plywood.

I will have to do a search to find the post, but somebody here posted a picture of a really cool idea where they made a MDF donut that they glued to the inside end of a port. Then they rounded over the inside and outside edges of the donut to create a very smooth entrance for airflow. I plan to copy this. Any comments about this?

[CokewithLime]

Thanks again for the info. The glue in this situation won't need a whole lot of strength because the ports themselves virtually weigh nothing and there will be no (hopefully) real stress working on them. The only real stress they will see is when I use my router with a flush trim bit to match the size of the plywood flange hole to their inside diameter, then the load of the bearing of the roundover bit that does the "flare" in the plywood.

I will have to do a search to find the post, but somebody here posted a picture of a really cool idea where they made a MDF donut that they glued to the inside end of a port. Then they rounded over the inside and outside edges of the donut to create a very smooth entrance for airflow. I plan to copy this. Any comments about this?

Why spend extra money on pre-made ports if you already have a router, plus flush trim and roundover bits - just purchase ABS or PVC tubing of the correct diameter then cut a small square of mdf/ply a 1/2" bigger than the OD of the tubing.

Next cut a circle the diameter of the tubing all the way through the small square piece, then glue the piece on the back of your baffle where you want the port to be. After the glue has dried, glue and insert the ABS or PVC tubing (that was already cut to the required length) into the opening of the block, making sure it is pushed tight against the back of the baffle.

After the glue on the port tube has dried, drill a pilot hole large enough to take your router flush trim bit from the front of your baffle, centered in the opening in the small block behind the baffle. Finally do a router pass from the front of the baffle with your flush trim bit and another with the roundover bit - you're done, a great looking custom port.

It may read as a lot of steps but it is just as quick to do this as is is to do the cuts for pre purchased ports and IMHO looks a lot better than most cheap plastic ports.

btw - GG works great for use with ABS/PVC tubing