I just recently built a brake rotor forge. Can I use coal in it even if I don't have a clinker breaker? would it be a problem if I don't have one? 

 

I attached a picture of my fire pot.

When clinker builds up it tends to reduce the air flow. Stop the air to the forge for 30 seconds to a minute and remove the clinker. When it cools it sticks together and many times comes your in large chunks or as an entire piece.

Hate to be the bearer of bad news, but while that pot will last for a long time, that grate you have isn't going to last five minutes after you get some heat on it.

 

That looks like some very thin sheet, and it will melt very quickly.  Expect your fire to drop down the pipe as soon as that happens.

 

A grate can be made from some 1/2" rebar laid across the opening, or a steel end cap with a hole drilled in the middle of it.

Thanks VaughnT. You are very correct about me needing to get a new grate. I just threw that grate together one afternoon with tin snips and 22 gauge sheet. I will replace it soon.

in the forges I make I stopped using clinker breakers. I just use some 3/8" rebar of 5/8" depending on the size of the fire pot. I have been burnning the one forge for the last 5 years and only had to re weld one bar. keeping your fire clean is a thing you will just have to do.

I used a brake drum forge for several years, and it didn't have a clinker breaker in it. A coal forge can run perfectly without a clinker breaker, what you have to do is, if you start forging in the mornin, by lunch you will need to take a piece of 3/8" round bar with a point on it to "poke" a hole through the clinker. I did this for several years, and was even able to forge weld. 

I would though suggest that you make a better grate. Currently I use a grate made out of 1/2" rebar in my forge.

I made a rotating clinker breaker for my forge, and I don't really use it. A basic grate should work fine.