Note 11 - Income Taxes - Deferred Tax Assets (Liabilities) (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Vacation accrual	$ 2,900	$ 5,450
Allowance for doubtful accounts	743	1,202
Reserve for obsolete inventory	305,425	200,118
Business tax credit carryover	30,935	30,935
Deferred Compensation	16,787	8,500
Net operating loss carryover	4,646,434	4,906,974
Excess of book over tax depreciation	(71,116)	(296,227)
Valuation allowance	(4,932,108)	(4,856,952)
Long term deferred tax asset