Fire under a silnylon tarp (Video)

I've gotten all kinds of pin holes in tarps. Just throw some seam seal or tape over it and it's no problem. My last tarp almost had more duct tape than nylon but I got a ton of use out of it and it was super cheap ($20).
You are right about sparks not affecting tarps when they are wetted out, which is good because you need to keep the fire sheltered in the rain (more chance of a spark hitting). If there is no wind then pitch it high like a canopy. If you are going to make a bigger fire under the tarp it's best to pitch your tarp so it's flat or even slightly concave. If you have a high center point, like if it was almost a pyramid shape, then the heat can collect there with no way to escape and potentially melt the nylon. An A-frame is better because even though it has a high point, it vents out along the ridge, however flat is the safest.

90% of avoiding sparks is choosing wood that doesn't pop. Hardwoods like oak, manzanita, madrone are the best while really resinous woods like cedar and some pine are bad. Redwood can be the worst, sometimes a big burning log will launch quarter sized chips of hot coal at you. I've slept within a couple feet or less of oak/madrone fires and I'm not worried. I'm actually thinking about creating a silk bivy for my down bag so I can dry it out by the fire while winter camping without worrying about stray sparks.

It is possible to keep a fire going without keeping it under your tarp. Placing it under a dense tree canopy is the most important thing. And it needs to be a big, hot fire. When you place a bunch of wet wood propped up above the fire to dry out, that creates more shelter for the fire. If you can do some sawing for dry wood and keep putting on 1/2 dry and 1/2 wet wood it will burn easily, putting on all wet wood requires careful placement and micromanagement. It's good to have the wet wood leaned to be above the fire so the moisture evaporation doesn't suck the life out of the center of the fire.

On one miserable night when I needed to keep the fire going to sleep, I placed a bunch of hot coals into my cooking pot. When I woke up and the fire was drowned out with rain (usually doesn't happen, your body will wake you up when you get cold) I used those coals to get it started again. That might be a good technique if you want to cook in the morning (i never do).

using your pot to hold the coals sounds like a reasonable idea. Though if there's is resin it's going to be tough to get it out of the pot.

You could also dig a hole.

What I did is that I emptied my backpack, and then I tried out a bunch of kindling while the fire was roaring…

Then the next morning I used that to restart the fire and all was well.

I used a LOT of kindling as there was only wet material.

It was pretty easy to get the wet wood going once you have a good base fire. I would say that in about 5 minutes a web piece of wood would be on fire.

Another option is to use wet wood as the fire ring which dries out and then you can place the dry pieces on the fire.

We didn't have room under the tarp to store wood so we just took this approach and things were fine.

Yeah I usually go and split down a larger piece of wood to get the fire going so I don't waste a ton of fire starter, but I know how difficult it can be to find anything dry in open oak woodlands.

"If you have a high center point, like if it was almost a pyramid shape, then the heat can collect there with no way to escape and potentially melt the nylon."

Possibly, but you could use that to your advantage too. Take some diluted silicone glue, and glue a part of a reflective heet sheet to that area, and you will reflect that heat back down very well. Won't protect against sparks, but will protect the nylon from possible radiative heat damage.

Regarding protecting silnylon from sparks, wonder if some extra silicone coating in key areas might help some, as many forms of silicone is fairly heat and fire resistant by nature? More specifically, the silicones made for high heat applications and contact?

Thanks for the video. I'm a little wary of fire and nylon, but that video was a real eye opener to me. That was a pretty decent fire, putting off a lot of heat to be under a silnylon tarp. I get concerned about heat damage coming off my UCO single-candle lantern in a nylon tent. Haha…I won't be quite so worried about damage from a single candle anymore. In the past I always used my hand as a gauge. I figured if I could leave my hand above the lantern for an extended period of time without getting uncomfortable, I figured the distance was probably safe for the tent.

As to a down jacket in the Santa Cruz Mountains…you're a braver man than I am. ;-)

I'm slowly starting to warm up to down (pun intended), especially after some great advice I've been getting about the Sierras. But I've spent enough time in the Santa Cruz Mountains (I've worked there for a number of years) to know that they are WET. lol

To expand on Justin's comments regarding types of wood that seem to "spark" more than others, it's mostly a situation of "wet" wood vs. "dry" wood. "Wet" wood can be classified as being newly cut, with high resin (sap) content and also wood that has been exposed to rain/wet conditions for a period of time. What is happening when we burn "wet" wood and it pops is, the moisture in the wood has heated up and expands. If that liquid heat expansion is trapped in the wood fibers, it continues to build up pressure until we get a mini explosion with the "pop" we hear, sending a shower of sparks in all directions.
The obvious choice for all of us, when burning wood, is to find the driest (old dead is best) wood possible for our fires, as that will burn cleaner and hotter to keep us warm.

Besides my last name being what it is, I was also a fire fighter for 34 years.

Terry