tjdaggett Posted March 1, 2023 Share Posted March 1, 2023 Smiths, Good morning! I am making my small daughter a pair of free weights out of railroad spikes. There won't be any forging, as the shop door is iced shut and I won't be able to get in for a few weeks. Just going to file off the sharp corners on the spike end. The rust is already off. Railroad spikes without rust look surreal. The question: since I can't get to my forge and I have to do all of this in the house, I'm wondering if a kitchen oven set to 550F will be able to get the spikes hot enough to accept beeswax effectively. I know the BLO/beeswax/turp. finish goes on at a black heat ideally, which I believe is closer to 900-1000F. My guess is that since the weights will have a fabric wrap to function as a grip/cushion that they won't see much wear. Thoughts? Quote Link to comment Share on other sites More sharing options...
Glenn Posted March 1, 2023 Share Posted March 1, 2023 Beeswax melts at 145° degrees Fahrenheit, and has a flashpoint of around 400° degrees Fahrenheit. Turpentine can catch fire around 95° degrees Fahrenheit (35° Celsius) as that is the flashpoint. Linseed oil flashpoint is approximately 200° degrees Fahrenheit (93.3 °C). Flashpoint means the temperature at which a liquid ignites without warning when in contact with air. Quote Link to comment Share on other sites More sharing options...
tjdaggett Posted March 1, 2023 Author Share Posted March 1, 2023 Now that's curious. Why doesn't the mixed finish I referenced above ignite when applied to metal at a black heat? Also, I have no intention of putting the wax in the oven, only the metal. Then I'll apply the wax to the metal in the back yard. Quote Link to comment Share on other sites More sharing options...
JHCC Posted March 1, 2023 Share Posted March 1, 2023 "Black heat" simply means "Hot, but not yet hot enough to glow". The hotter degrees of black heat are too hot for the oil/wax/turps mix; at most, you only want a little bit of smoke. So yes, 550°F is plenty hot, maybe even a little too hot. However, if you're going to be transferring the spikes from a hot oven and taking them into the cold outdoors, they're going to be cooling down while in transit, so if you start at that temperature, they should be close to the right temperature by the time you get outside. Quote Link to comment Share on other sites More sharing options...
Glenn Posted March 1, 2023 Share Posted March 1, 2023 It is suggested to melt the beeswax, you use a double boiler. Water boils at 212° degrees Fahrenheit or about 50° degrees Fahrenheit above where the wax melts. The beeswax, BLO, terp mix can be applied at room temperature. Warm metal just means that it applies a little easier and flows into the nooks and crannies a little better. Quote Link to comment Share on other sites More sharing options...
tjdaggett Posted March 1, 2023 Author Share Posted March 1, 2023 Thank you kindly! I have that finish mixed up already, so I'll just use that and let the spikes dry in the garage, avoiding melting new beeswax altogether. Quote Link to comment Share on other sites More sharing options...
JHCC Posted March 1, 2023 Share Posted March 1, 2023 Applying to a warm/hot workpiece also accelerates the evaporation of the solvents and the polymerization of the oil, speeding the drying/curing process. Quote Link to comment Share on other sites More sharing options...
Glenn Posted March 1, 2023 Share Posted March 1, 2023 Linseed oil polymerization. What is it, and how does it work? Rabbit hole alert: https://www.sciencedirect.com/science/article/pii/St Quote Link to comment Share on other sites More sharing options...
Jobtiel1 Posted March 2, 2023 Share Posted March 2, 2023 18 hours ago, Glenn said: Flashpoint means the temperature at which a liquid ignites without warning when in contact with air. The flashpoint of a liquid is the temperature at which the liquid gives of sufficient vapor to form a combustible vapor/air mixture, it will not ignite without external ignition source at this temperature. What you are describing here is the auto-ignition temperature, which is the temperature at which a liquid will spontaneously ignite without external ignition source. This is quite cool to see, we did experiments to determine auto ignition temperature in the lab once and when you put something over to remove oxygen and kill the fire the liquid will ignite instantly again when you remove the cover. This is however not the case at the flash point. ~Jobtiel Quote Link to comment Share on other sites More sharing options...
Glenn Posted March 2, 2023 Share Posted March 2, 2023 A search for autoignition temperatures yield the following. A certain concentration of vapor in the air is necessary to sustain combustion, and that concentration is different for each flammable liquid. The flash point of a flammable liquid is the lowest temperature at which there will be enough flammable vapor to ignite when an ignition source is applied. Unlike flash points, the autoignition temperature does not use an ignition source. In other words, the autoignition temperature is the lowest temperature at which a volatile material will be vaporized into a gas which ignites without the help of any external flame or ignition source. As a result, the autoignition temperature is higher than the flash point. Beeswax flash point of beeswax is399.9 °F, (204.4 °C). There is no reported autoignition temperature. Turpentine autoignition temperature 428 °F (220 °C; 493 K) Linseed oil autoignition temperature of 650 F. Quote Link to comment Share on other sites More sharing options...
tjdaggett Posted March 2, 2023 Author Share Posted March 2, 2023 Thank you all! I love this place. Quote Link to comment Share on other sites More sharing options...
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