My husband works for a body/paint shop as a commissioned painter. He is paid by the "flag" hour ( i.e.- it pay's three hours to paint a bumper, so he is paid $ 19.00 per flag hour no matter the amount of time it actually takes him to paint the bumper)

Some weeks there may be very little work so his employer expects these 4 guys to sit around for $00.00 until the work comes in, this sitting around game can last for 2-3 days a week and then on Thurs. and Friday, it's shove as much work on them as possible even if they have to stay all night to complete the job. On the day's that they are sitting around it is very clear that they can't leave, but are not receiving any pay for sitting there. They are to be paid on friday @ 5:00 p.m. for that week.
These guys do not always make over $ 450.00 per week but usually do.

Also, they are expected to stand around hours after painting a car ( it goes back to the body shop for assembly, ect.) so they can wash the car that they are not paid to wash. Is it legal to force someone to stand around w/out compensation to wash a car. Some day's the owners do expect the painters to come to work just to wash a car with zero compensation and no othr work to do that day.
This week being a holiday week and only working 3 day's the boss' wife whom does the payroll decided since no one (except my husband) made much money, she is not going to write the checks for this week and add it all together for the next week and pay them the following friday. No one was ask if this would be okay, she just decided on her own. Well since my husband did have work, shouldn't he have gotten paid?
Also when the owner makes a mistake on an estimate to repair a car and fogets to get an insurance company to pay for something that needs painted, although my husband still has to do the work, the owner wants him to do the work for free, this adds up to some serious money every week. Although the owner made the mistake my husband is the one doing the free work.

He isn't in fact, "commissioned" in the true sense of the word. He is being paid on "task" basis, which is the standard in this type of work.

The "450 per week" you mention is irrelevant (I'm assuming you're thinking about the minimum weekly salary for exempt employee), because the type of work he is doing means he is nonexempt. Period.

Now, as long as 1) he makes at least minimum wage for all hours worked (including "engaged to be waiting", as defined below); and 2) he receives overtime when his hours worked exceed 40 in a workweek, there is no violation of any law.
http://www.dol.gov/dol/allcfr/ESA/Title_29/Part_785/29CFR785.15.htm
http://www.dol.gov/dol/allcfr/ESA/Title_29/Part_778/29CFR778.112.htm

Thank you for your response.
If you don't mind, I would like a little better clarity on a few things.
Please forgive me if some of what I ask sounds repetitive, but some of the links provided did not work.

No these guy's are not always earning minimum wage,(uncommon but does happen) and are not compensated for anything over 40 hours. They are paid by the flag hour, flat rate of $ 19.00 per flag hour, no matter how many hours they are sitting there waiting to engage, could be 40 hours have been as many as 75 hours in a week. The other painter worked m-f 40 hours (well mostly sitting there waiting for work) didn't get the cars he was to paint until the end of the day on friday, he then was told to work sat and sun so the cars could leave on monday, no pay for m-f for waiting to engage, and was not allowed to leave the shop. He was then told to paint the cars on sat and sun which he did, working more that 12-14 hours both days, but was not compensater for anything above what the flag hour paid.

Also, is it okay to ask these guys to paint something for free when to owner makes a mistake on something and forgets to charge the car owner for?
This isn't every once in a while, it has become daily to the point these guys are giving away hours a day. Making one wonder if it is done on purpose to not compensate these guy's for their pay "because the boss made another mistake on an estimate" and collect all the funds for the boss himself. The boss continually adds extra things for the painters to do, but are not paid for-
such as priming and blocking is actually the body mans job and is included in the price of body work, but the painters are the ones that do that job, without pay, imagine sanding an entire bed of a pickup for free by hand-happens all the time.

Or to make these guy's to wait hours to wash a car for free, i mean, if this is by "task pay" and this is not included in the written ticket that tells them what work to perform. ( no compensation again for the standing around either) can a person be expected to wait hours without pay, to wash a car without pay.

What about holding onto someone's check when payday is supposed to be on friday, but the boss doesn't "feel" like writing a check, and the employee is made to wait until the next week. ( this has happened more than once, mostly when the owners were buildjng a home and couldn't pass out pay checks because they were to busy picking out floor tile )

If the links didn't work, it would only be because the site was not available; the links are fine, I just tried them this minute.

OK, on to the questions.

No these guy's are not always earning minimum wage,(uncommon but does happen) and are not compensated for anything over 40 hours. That's a violation of wage and hour law.

They are paid by the flag hour, flat rate of $ 19.00 per flag hour, no matter how many hours they are sitting there waiting to engage, could be 40 hours have been as many as 75 hours in a week. Perhaps I didn't explain it clearly. They don't have to be paid a specific hourly rate to "sit and wait"; they don't have to be paid ANY hourly rate is "sit and wait". They just have to average minimum wage for every hour worked (which includes waiting time) and be paid for overtime at the premium portion (the .5 part of 1.5) only. What this means is that the washing the car or sweeping the floors or sitting and waiting is work time and must be used in the calculation.

Let's look at an example.

Total flag pay for the workweek = $800
Total hours worked (including everything mentioned above) = 50 hours

Regular rate of pay as defined by the FLSA = $800/50 = $16/hr

Overtime premium = $16 * 10 hrs OT * .5 (premium portion-straight-time portion is already included in the flag pay) = $80

Total pay due $880 (flag pay + overtime premium)

If the employees aren't getting at least that much, the employer is in violation of wage and hour law, and can file claims for unpaid overtime with the state Dept. of Labor.

Regarding payday, Oklahoma law requires that employees be paid on regularly scheduled paydays, which must be at least twice per month (semi-monthly) and payday must be no more than 11 days after the end of the pay period. If the employer doesn't have "time to pay" his employees on the regularly scheduled payday, I'd not only be filing another claim with the state DOL, I'd be looking for another job. Good auto mechanics/technicians are hard to find.