1 Steam Cars : Phorum
General Steam Car topics
cooking firewall paint
Posted by: SSsssteamer (IP Logged)
Date: August 03, 2005 02:31PM
<HTML>On our 1916 Stanley Mt. Wagon, the paint on the fire wall is taking a beating from the heat. I do have a firewall insulator. The smoke bonnet is double walled and well insulated. The 30 hp boiler is wrapped with about 3/4" insullation. I have everything wrapped with insullation. The exhaust from the boiler dumps underneath the car like on a condensing Stanley The hood has about a half inch gap between it and the firewall to let the heat out. It is this escaping heat that is bubbling the paint on the firewall. I have seen this problem on other Mt. Wagons as well. What are the suggestions to prevent this damage? More insullation? A special paint? A wider gap between the firewall and hood? A firewall that is covered completely with tin? Any suggestions?</HTML>
Re: cooking firewall paint
Posted by: Andy Patterson (IP Logged)
Date: August 03, 2005 04:25PM
<HTML>Maybe using one of the ITC coatings would at least not bubble. Possable a pigment could be added.
[www.anvilfire.com];
[www.anvilfire.com];
Re: cooking firewall paint
Posted by: Ben in Maine (IP Logged)
Date: August 03, 2005 05:48PM
<HTML>Hi Pat,,,Good to hear from you,,,600# is about 380 F ??[check this,,,it's a hot day an I just came in] ,,, ,,,,the smokebox is around 500 F ,,,, How much covering is on the smokebonnett,,,,Now we must look at all the mountainwagons,,,,Dont forget Carl s hoods survived pretty well,,,generally better than the others,,,hmmm,,,,Cheers Ben</HTML>
Re: cooking firewall paint
Posted by: George (IP Logged)
Date: August 03, 2005 08:57PM
<HTML>Pat,
Have you put a thermocouple into the flue to see how high your flue gas temperature is? Are you keeping your water level high enough to prevent very high flue gas temperatures---the article on Professor Wendell Mason illudes to keeping the water level higher than many do. What is your burn rate, is it the factor 6GPH on the 26" boiler or is it souped up to 8GPH or higher? Putting in an economiser above the boiler could drop the flue temperature several hundred degrees and add 5%+ to the overall efficiency and boiler steam output, several have done this on there 20HP boilers as the flue is not usually insulated as it is so close to the firewall.
Best to you, George</HTML>
Have you put a thermocouple into the flue to see how high your flue gas temperature is? Are you keeping your water level high enough to prevent very high flue gas temperatures---the article on Professor Wendell Mason illudes to keeping the water level higher than many do. What is your burn rate, is it the factor 6GPH on the 26" boiler or is it souped up to 8GPH or higher? Putting in an economiser above the boiler could drop the flue temperature several hundred degrees and add 5%+ to the overall efficiency and boiler steam output, several have done this on there 20HP boilers as the flue is not usually insulated as it is so close to the firewall.
Best to you, George</HTML>
Re: cooking firewall paint
Posted by: Graeme Vagg (IP Logged)
Date: August 04, 2005 01:36AM
<HTML>If I had a similar problem I would put a reflective insulating lining on the heated side of the firewall (could be silver sided builder's insulation or silvered fibreglass type material used over steam pipes or vent duct work). I would use a good heat resistant paint such as engine or exhaust manifold enamel rated for up to 1200 deg F - sold from auto accessory shops. The silver HR paint could also be used on the hot side of the firewall.
Graeme</HTML>
Graeme</HTML>
Re: cooking firewall paint
Posted by: Ben in Maine (IP Logged)
Date: August 04, 2005 02:30AM
<HTML>Was this a problem in 1906 I wonder,,,Cheers Ben</HTML>
Re: cooking firewall paint
Posted by: SSsssteamer (IP Logged)
Date: August 04, 2005 03:05PM
<HTML>The paint on the hood is doing well without any problems. It is the firewall above the hood that is getting cooked from the rising heat. The smoke bonnet is double walled and is insulated within and on the outside. The smoke bonnet is doing it's job well, as is the insulation glued to the inside of the hood. The exhaust flue is pollished stainless without any insulation on it yet. It's turn with insulation is coming. ;>) I do not have an economizer in the smoke bonnet, but I do have an excellent exhaust feedwater heater. The burn rate has to be low as I only am using number 56 jets and the Baker burner doesn't even howl when cruising. It lets out a few howls when I am first firing up from cold. The paint damage is only occuring on my firewall above the hood when the Mt. Wagon is parked. When I am rolling, the firewall is air cooled. I always keep the water level in the upper half of the boiler, usually about 4 inches from the top on a 16" tall boiler. I have driven the Stanley about 120 miles so far and the water level hasn't seen below the middle of the boiler yet. The firewall below the hood hinges is insulated with pollished stainless steel and 3/16" insullation. I do not have an air gap between the firewall insullation and the firewall as was done with most early noncondensing cars. An air gap may not help the firewall paint above the hood. When I am parked, I have been leaving the hood's top flap open to let the hot air out. Maybe the paint is too fresh and the solvents have to be cooked out of the paint. I will let it get crisp and then I will sand down the bubbled holes and try fresh paint on it again. The wood firewall was first sealed with a fiberglass resin and hardner. Then it was sanded smooth. Next a primer surfacer was used followed with a sealer. Finally three coats of color were applied. That is quit a pile of paint to be throwing heat to. Possibly I may have to strip the firewall's wood bare and put only a minimum of heat resistant paint on the wood. Thank you for the advice. Did they have this problem when they were new? Probably not because they didn't use all the wood fillers and types of paint that we have today. Our high gloss finishes are whole different formulas than they used in about 1910. I have many vintage photographs of Mountain wagons in service and in 9 out of 10 photos, they had their top hood flaps and smoke bonnet lids propped open while parked.</HTML>
Re: cooking firewall paint
Posted by: Ben in Maine (IP Logged)
Date: August 04, 2005 05:32PM
<HTML>Hi Pat,,,Now your comments spark me to recall,,,Carl said to put the paint thinner on the hood than the rest of the car,,,The turn of century varnish was maybee more pourous,thus venting the vapor from the wood and stuff below,,,I think the vent flap is open more to keep clean air in the firebox for startup,,,The Black car prefers to be in motion as I open the main burner valve,,to get a breath of fresh air,,Question,,,, Did the old firewall shield fit the hood outline,, and was it foreward enough to allow air to come up BEHIND IT ,, and go out by the hinge,,,,Just a thought,,,,,Thanks for the description,,that helps looking at the problem a lot,,,,Cheers Ben</HTML>
Re: cooking firewall paint
Posted by: SSsssteamer (IP Logged)
Date: August 05, 2005 05:10AM
<HTML>Dear Ben, I have a unique problem here in that the 1915 and 1916 Stanley Mountain wagons had seperate dash boards that allowed the chassis to be driven without the body in place. The dashboards were about 5 inches shorter than where the hood hinge mounted on the firewall. The dash boards were insulated without any air circulation behind their heat shields. To have air circulation in the upper 5 inches of exposed firewall would be an akward order. So the upper 5 inches get the no air circulation heat shielding. Since there are about only 6 of the 1915 and 1916 mountain wagons left, there isn't much to go on of what is correct. You are right about using thin breathable paint on the firewall and hood. When the wood heats up, it's trapped air has to escape to somewhere. In my case, it is blowing bubble like bubble gum. It is good to hear from you. My hard drive died last month and I lost your email address in the process. Everything is new and working again.</HTML>
Re: cooking firewall paint
Posted by: George (IP Logged)
Date: August 06, 2005 04:55PM
<HTML>Pat,
Have you considered painting the firewall with a thermal insulating coat, "http://www.techlinecoatings.com" sell a few products that a few of us have used on engine parts. They need to be cured/baked at 300 degrees but sounds just by firing up the beast it would reach that temperature easily and cure in place. If memory serves me correctly believe about 80% of the heat trying to enter it is rejected back. Think it would be wise to stick a thermocouple into a 1/16" hole in your flue and find out what the temperature is. You could paint/coat the inside of the flue pipe and end up with the same results.
Best, George</HTML>
Have you considered painting the firewall with a thermal insulating coat, "http://www.techlinecoatings.com" sell a few products that a few of us have used on engine parts. They need to be cured/baked at 300 degrees but sounds just by firing up the beast it would reach that temperature easily and cure in place. If memory serves me correctly believe about 80% of the heat trying to enter it is rejected back. Think it would be wise to stick a thermocouple into a 1/16" hole in your flue and find out what the temperature is. You could paint/coat the inside of the flue pipe and end up with the same results.
Best, George</HTML>
Re: cooking firewall paint
Posted by: SSsssteamer (IP Logged)
Date: August 06, 2005 06:14PM
<HTML>George, I do not have a thermocouple to use for measuring the heat in the smoke bonnet. The damage happens when the Stanley is sitting still (with the main fuel shut off)and heat is rising out between the hood and the firewall. Too much rising heat and too frail of paint. Today I am going to insulate my exhaust stack and I will see if that helps. I had better hurry up before all of my firewall paint is ruined. " I will prevail over the red barron".</HTML>
Re: cooking firewall paint
Posted by: Dick Vennerbeck (IP Logged)
Date: August 08, 2005 12:48AM
<HTML>Pat,
The metal hood is able to loose the heat much faster to the surrounding air. It's insulated on the hot side and surrounded by cooler air on the paint side. The paint on the firewall is (I think) on a wooden surface. The paint gets overheated because on one side it's insulated by the wood and the other side is continually bathed in hot gasses. It is just the opposite of the hood. The paint faces the hot side and the cold side is insulated. The only fix would be to find a paint that can withstand a higher temperature or maybe even not allowing the hot gasses to excape between the hood and firewall.
Good Luck,
Dick</HTML>
The metal hood is able to loose the heat much faster to the surrounding air. It's insulated on the hot side and surrounded by cooler air on the paint side. The paint on the firewall is (I think) on a wooden surface. The paint gets overheated because on one side it's insulated by the wood and the other side is continually bathed in hot gasses. It is just the opposite of the hood. The paint faces the hot side and the cold side is insulated. The only fix would be to find a paint that can withstand a higher temperature or maybe even not allowing the hot gasses to excape between the hood and firewall.
Good Luck,
Dick</HTML>
Re: cooking firewall paint
Posted by: SSsssteamer (IP Logged)
Date: August 12, 2005 05:58AM
<HTML>Well, I did all of my insullation. Exhaust stack, steam lines, and even I insullated the water automatic. I went steaming with it yesterday to a car club picnic and I used it as I usually do. The blistering seemed to be halted. Either I have cooked out all of the vapors from the paint, or lets hope that I have cured the problem. Now it is time to repaint the firewall. Thank you for all of the ideas on how to stop the cooking of the firewall paint. This time, the depth of the paint will be kept to a minimum.</HTML>
Sorry, only registered users may post in this forum.