Seeking advice on material choice for awning bracket spacer

[outback97]

Regarding the pricing of Delrin and other plastics:

If you live in any sort of big city, check to see if you have an industrial plastic supply company nearby. Tap Plastics, RidOut, etc. They always have a scraps/cut-offs/rems bin that is pennies on the dollar, and usually sold by weight. For the size of the chunks outback97 used, I doubt I would have paid more than $4.00 out the door.

That's good to know, thanks Herbie. McMaster-Carr is so convenient as I get stuff from them next day without driving anywhere, but I'll take a closer look at other options next time I need some plastic for a project. Unfortunately most industrial supply places are nearly an hour roundrip from me and open only M-F, so it's hard to take advantage of them.

 

[rayra]

I probably should have sought clarification before I worked on this, but can you tell me more specifically what has worked for you? Honestly on this project it's not something I want to spend a ton of time with (it's a spacer for an awning bracket) but if I work with this stuff in the future it might be nice to know how to make it look decent.

On my lunch break I went down the street to a Fastenal store and got the finest grit wet / dry paper they had, 1000. After wet sanding for a while with my scrap piece, I could get the surface smooth to the touch, but it just looked like a brushed gray appearance and still quite whitish at a high angle of incidence.

Next I put a little tiny bit of clear finish on it and wiped it down, now that look I can live with, as it did get it closer to black.

ironically the 'tooth' of the sanding might actually get that claer coating to stick a bit, but don't be surprised if it flakes off like a sunburn. I did some replica sci fi props with some delrin bits and I wound up doing a lot of wetsanding. I took it beyond 1000, might have been 2000. But I was also working with a curved surface, best I got was a satin / semi-gloss.
If you are working a flat surface I suggest you get a flat pane of 1/4" glass as your backer for the wetsanding, keep things very wet, and as you up the grit also lighten the downpressure. That will get it about as smooth as practicable.
The other advice is choose carefully which face you cut, such that the cut sides are hidden / face to face with brackets etc, and not the 'hero' side. Saves a lot of trouble / work that way.

 

[outback97]

ironically the 'tooth' of the sanding might actually get that claer coating to stick a bit, but don't be surprised if it flakes off like a sunburn. I did some replica sci fi props with some delrin bits and I wound up doing a lot of wetsanding. I took it beyond 1000, might have been 2000. But I was also working with a curved surface, best I got was a satin / semi-gloss.
If you are working a flat surface I suggest you get a flat pane of 1/4" glass as your backer for the wetsanding, keep things very wet, and as you up the grit also lighten the downpressure. That will get it about as smooth as practicable.
The other advice is choose carefully which face you cut, such that the cut sides are hidden / face to face with brackets etc, and not the 'hero' side. Saves a lot of trouble / work that way.

Thanks for the additional info, rayra, I appreciate it.

To clarify on my clear finish, it's so minimal that all it's doing is reducing the cloudiness and not really building up like a lacquer or coating. Apply tiny amount, wipe down with a rag. Hopefully I'll not have any peeling issues.

 

[rayra]

You're welcome.


You'd might do just as well wiping it with armor all or something like Turtle Wax's Trim Restorer goop. But once you do that you'll be doing it a couple times a year forever.

 

[javajoe79]

I don't see anything except specialty adhesives sticking to delrin for too long but maybe it will.

 

[rayra]

Yep, akin to nylon and teflon and HDPE2, 'slippery' polymers, not much works on them, except mechanical fasteners and fusing them to themselves.