Jackson's : Museum : Alu-Pro : 18x45mm : Secondary Crossbar Sets

Jackson's Museum Alu-Pro 18 X 45mm Secondary Crossbars Are Made From Aluminium, Providing A Strong, Stable Framework That Helps Maintain The Overall Rigidity Of The Stretcher, Even As The Canvas Expands And Contracts With Changes In Moisture. Your Canvas Would Need To Be Over 120cm Long On Its Longest Side For You To Need A Primary Crossbar For Structural Reasons. If Your Canvas Is Over 240cm On The Longest Side, You Will Require A Secondary Crossbar.Jackson’s Alu-Pro Secondary Crossbars Have A Depth Of 18mm And Are Compatible With All Jackson’s Alu-Pro Aluminium Stretcher Bars And Primary Crossbars. If Your Canvas Is Large Enough To Require Secondary Crossbars, Use The Same Process To Install Them As You Did With The Primary Crossbar. The Secondary Crossbars Need To Be At Right Angles To The Primary Crossbar And Attach Centrally To The Primary Crossbar’s Sides And The Middle Of The Internal Side Of Each Sidebar. The Only Difference Is, As Well As Attaching The Bars With One Support Connector Each, You Will Also Need To Attach One Cross Connector Per Bar, This Makes A Total Of Two Support Connectors And Two Cross Connectors Per Full Secondary Crossbars Installation.For A Frame That Features A Primary Crossbar And A Secondary Crossbars, You Will Need:- A 4mm Allen Key, Preferably An Alu-Pro Allen Key- Four Jackson's Alu-Pro Aluminium Stretcher Bars Of Whatever Size You Like- A Primary Crossbar The Same Length As The Short Sides Of Your Frame- Four Alu-Pro Corner Connectors (sold Individually)- Four Alu-Pro Support Connectors To Fasten The Crossbar To The Stretcher Bars (sold Individually)- Two Cross Connectors For Supporting Central Joins Between Primary And Secondary Crossbars (sold Individually)For More Information About Alu-Pro Products And A Series Of Assembly Tutorials, See the Alu-Pro Product Showcase On The Jackson's Blog.