Bimini frame parts supplier?

[MinUph]

I am no canvas person but have a pontoon where the Bimini is not tight enough and puddles. I may need to lengthen the short frame member to tighten it up. From the looks of it just adjusting might not do it. I didn't have any tools last week to try this week I will.
  But anyway where might I find some square pre bent tube if I need to replace the short member(s)?

[Mike8560]

EI'VE not seen pdebent square.  7:8" round yes.
Tri vatages  has the square fittings if you can get it  bent is there a local canvas shop that may bend it fir you?