Note 12 - Segment Information - Segment Reporting Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	May. 31, 2015	May. 31, 2014	May. 31, 2015	May. 31, 2014
Operating Segments [Member] | Agricultural Products [Member]
Revenue from external customers	$ 6,365,000	$ 7,562,000	$ 11,681,000	$ 12,004,000
Income (loss) from operations	579,000	599,000	1,018,000	396,000
Income (loss) before tax	538,000	542,000	937,000	301,000
Total Assets	25,330,000	26,147,000	25,330,000	26,147,000
Capital expenditures	55,000	162,000	133,000	574,000
Depreciation & Amortization	126,000	136,000	266,000	256,000
Operating Segments [Member] | Pressurized Vessels [Member]
Revenue from external customers	476,000	475,000	1,003,000	898,000
Income (loss) from operations	(5,000)	(77,000)	(66,000)	(109,000)
Income (loss) before tax	(11,000)	(85,000)	(78,000)	(125,000)
Total Assets	2,765,000	2,715,000	2,765,000	2,715,000
Capital expenditures		16,000	2,000	27,000
Depreciation & Amortization	29,000	27,000	53,000	54,000
Operating Segments [Member] | Modular Buildings [Member]
Revenue from external customers	409,000	537,000	1,058,000	998,000
Income (loss) from operations	(97,000)	(114,000)	(164,000)	(240,000)
Income (loss) before tax	(104,000)	(120,000)	(177,000)	(249,000)
Total Assets	2,659,000	2,708,000	2,659,000	2,708,000
Capital expenditures	(2,000)
Depreciation & Amortization	52,000	37,000	85,000	74,000
Operating Segments [Member] | Tools [Member]
Revenue from external customers	554,000	895,000	1,351,000	1,806,000
Income (loss) from operations	(63,000)	36,000	(45,000)	102,000
Income (loss) before tax	(69,000)	(2,000)	(83,000)	64,000
Total Assets	3,034,000	3,438,000	3,034,000	3,438,000
Capital expenditures	5,000	1,000	5,000	10,000
Depreciation & Amortization	30,000	28,000	59,000	57,000
Operating Segments [Member]
Revenue from external customers	7,804,000	9,469,000	15,093,000	15,706,000
Income (loss) from operations	414,000	444,000	743,000	149,000
Income (loss) before tax	354,000	335,000	599,000	(9,000)
Total Assets	33,788,000	35,008,000	33,788,000	35,008,000
Capital expenditures	58,000	179,000	140,000	611,000
Depreciation & Amortization	237,000	228,000	463,000	441,000
Revenue from external customers	7,804,111	9,468,996	15,093,239	15,706,331
Income (loss) from operations	414,144	443,891	743,293	148,955
Income (loss) before tax	354,007	$ 334,100	598,807	(9,102)
Total Assets	$ 33,788,028		33,788,028
Capital expenditures			$ 139,994	$ 611,211