Contractor Provided Financing

[James Sloan]

I was wondering, can/do contractors sometimes provide customer financing for some final portion of a project, if it goes over-budget. For instance, if a customer pays reliably the first 40 K of a project's costs, are there some who would be willing to carry the last 20 K for the interest payments? 

If so, how can I find them?

In my case, I really want to replace my cabin's vinyl with exterior split-log siding, but have only enough to finish the interior. 

Thanks in advance.