Newbie and Novice

Howdy y'all,
I need some advice on two things, the first being exterior window covers. I plan on making them myself (I haven't sewn in 30 years). I have a Sailrite sewing machine and want to know if there is a material besides Stamoid that I could use. What's the average lifespan? Stamoid is sooo expensive. It doesn't look like it would be too hard. Or, should I take it to a pro? Any hidden catastrophes I need to be aware of?
I'm also trying to perk up the teak. Removing the varnish has been a royal pain in the gizzard that I don't want to EVER repeat so I am oiling it. Have I screwed up?
Thank you for your advice and have a rootin tootin day.

I was hoping someone would answer your question about the right material for window covers. That's on my list too. I need to replace the big one and make a few more. Probably hatch covers and a cover for the throw ring, too.

As for teak, I don't have much on this boat, but I had one with a teak swim platform. I always oiled, never varnished. You do have to keep up with it, and it doesn't look as good, but I think it's easier.

Howdy Capt. Tom and thank you for your reply. We ordered Stamoid today for the windows, and so the sewing will begin next week. Fingers crossed, I will be able to sew a straight seam and they will fit.
Been working on the teak a bit at a time using Starbrite and I think it
looks great but know it will take some effort to keep it looking bright and shiny.
Got a kyak today, all plastic with no windows or teak, paint, engine, electronics, etc. Less is more...nah!
Happy trails,
Ranger

Staying on top of it has to be better than stripping it again.