Feedback on way to extend x axis

Hello All,

I am looking to extended my x axis to about 1800mm, y axis will remain the same. I looked for 1800mm Makerslide but can not find any, so here is what I am thinking of doing,
I am thinking of purchasing (2) 1000mm Makerslide and using two steel rods down the bolt holes for alignment (fixed with epoxy on one side), then using aluminum brazing rods to braze the two pieces together. I know I will have to do some filing and sanding to smooth out the joint area and use braces off the waste board. I would like to get input on how this sounds. I know there is a site I think Openbuilds has add on V Slot but they only also have 1000mm, and it would be more expensive than the route I am thinking of doing.