Fire Doors - Getting stuck!

I am finding my fire doors increasingly difficult to open. Has anyone else found the same?

I believe my problem is caused by a build up of tar etc on the inside of the fire door which presses against the back of the boiler when the doors are opened. I have attend a few rallies this year where the coal has been far from ideal - very smoky with little heat. A temporary solution is to operate/force the doors to open a few times.

Is there a simple fix other than completely removing the doors and mechanically cleaning them?

I give mine a really good sluice down with liquid WD40, once cold, after steaming: and rattle them back and forth vigorously. I also ground up a short bit (1" long) of broken 3/4" file at the tang end, that fits through the door. This can be held by a pair of pliers on the tang and with the doors almost closed twisted and scraped around the backface of the door, pulling towards the rear of the tender. It doesn't get rid of all the soot, but it helps, and is more difficult to descibe than do. The other possibility is to make the doors easier to remove by using R clips instead of split pins, although I haven't got around to that yet.
Tim

My fire doors were getting very hard to open & I was in danger of bending the lever. I tried all sorts of potions all to no avail so ended up taking the doors off. I found that in the middle of each door was a sort of baked on powder that had built up quite thick. A stanley blade soon removed it & when the doors were replaced it was like new with virtually no resistance at all. I reckon next time they get like that I'll drop the ashpan & stick my arm up into the firebox withthe doors shut & try & scrape clean them with a small scraper or blade. There was nothing on the boiler that needed removing it was just the doors that needed cleaning.

I went for it yesterday and removed my doors. Took off the bottom guide bar and the split pins on the doors. Like this I managed to wiggle the door on the operating liver off. To get the other door off I had to take the split pin off on it's levers pivot to get enough wiggle to be able to manoeuvre the door off.

On inspecting the doors there was a baked on deposit of soot in the shape of the fire hole. This was not particularity thick. Easy to scrape off. The only problem refitting the doors was the bolts hold the lower guide bar in are pigs to get in.

On testing the doors it was as Steve says - like new - very little force required.

Conclusion - well worth cleaning the inside of the doors every no an then.

I have always had trouble with this, the biggest problem I had was getting the bottom slide bar back on with the two very short set screws. I have replaced these two screws with longish studs. The nuts on these studs can be slackened back sufficiently to allow the guide bar to be lifted out. The doors can then be removed from the central pivots and sraped clean, they are then replaced in reverse order. Using studs makes the operation very easy, I can get my fire doors off, cleaned and replaced in ten minutes.