wood fire grate

[Frosty]

Deb just bought a RV and is making all kinds of plans for "fun" with it. Right now I'm walking on eggs, it's her baby and I'm . . . Uh, Nevermind. It's fun seeing her have so much fun even if she can get sensitive over . ?

What I'd like to do is make a folding camp fire grate. I have it planned but don't know how far to space the bars. The individual bars will be 3/8" x 1" flat. They'll all be punched and drifted to take a 1/2" rd. hinge. When folded closed the fire grate bars will pass similar to scissor blades but without the pinch points. There will be cross bars connecting each grate half lengthwise. Each side gets two, one just down from the top one just up from the bottom so each half could be used as a fire grate across supports. In use it'll stand off the ground as a V, a pair of simple gate hook like thingies will stop it from flopping flat. From the end it'll look like an upside down capitol "A". It's simple, reasonably light and folds flat to fit in the RV basement.

So, there it is, what is a good distance between bars? 

Thanks. And of course I'll take pics once I get it started.

Frosty The Lucky.

[4elements]

I would copy the spacing from a barbecue if it was for grilling, 2 or 3 times that for coffee pots and pans. Maybe one side of each spacing.

[Frosty]

I was afraid of that I confused things describing it. It's not a grate to set things on though it'll work for that if taken apart. I want one to hold burning wood at a camp site. I'm thinking the bundles you see at convenience stores, etc are around 14" long so I think I want this one to hold say 16" +. I wish I could think of what folk across the pond call them but it's just to hold burning wood. Sort of like the fire grate behind andirons but V shaped. 

I have a steel pan to put  under it even.  I'd just like a good distance to space the bars.

Frosty The Lucky.

[Daswulf]

Something like a self feeding fire, or just an elevated fire? Sorry I don't have any spacing ideas other then to make it as tight as the smallest embers you want to keep elevated. 

[4elements]

I got it now. Well since just holding the wood isn't much of an issue, it seems to me that keeping the coals from falling out while letting air in are the main constraints. Since the top of the fire won't have much coals, id think variable spacing with it wider at the top and about 3/4" at bottom would serve. Just my opinion, take it for what its worth.

[Jasent]

I imagine them holding the wood on the flat (1" side) but that would make it tough to punch for 1/2" round hinge so it will hold the wood with the 3/8" side?  I would think a 1" gap would be a even break between ease of building the fire and getting good air flow with out have too many coals falling out 

[Charles R. Stevens]

Jerry, you have been playing with Fire long enugh, the only reasion for a grate is to get air unde the fire to make it burn hotter and brighter. Fire will burn longer setting in its own ashes. Heck, 1" on 2" centers I'd more than close enugh to hold up the fire. 

Maybe even 4" centers, lol. 

 

[Irondragon Forge ClayWorks]

The grate in my freestanding fireplace has gaps of 1/2 inch with the bars 3/4 inch wide. It burns logs fine down to nothing but ash.

[SmoothBore]

Sounds like you're talking about a folding, or collapsible sort of "Brazier".

Rather than the inverted "A" design, ... I would think a basic "X" shape, would have benefits of functional simplicity.

By making it slightly asymmetrical, and joining the "long" ends of each half together, ... the the ends of the opposing rows of flat bar will allow enough "bypass" for the assembly to fold completely flat.

Pipe spacers of 1" to 2" in length, inserted on the center pivot bar, ... between each piece of flat bar, ... will give you whatever spacing you desire, ... and guarantee the flat stock will have plenty of clearance to fold into itself.

Rather than "Gate Hooks", ... a length ( or 2 ) of chain, welded on one end, and hooked over a peg at the other, ... would serve as a means of adjusting the spread of the "legs".

 

.

[4elements]

Hi Frosty. since you didn't include a drawing, and my brain's text to visual translator is iffy at best, I've made a sketch of what I think you are talking about. correct me if I am wrong. I would still opt for 1/2" to 3/4" spacing. Instead of individual spacers you could make a J bend on the bottom of each piece and put the pivot hole through both sides of the lower end of the J. 

[ianinsa]

Well Jerry I hope "your" RV lives up to it's potential  and as for the grate spacing I have always used the one and a half thumb width spacing,  not  exactly scientific but it's always worked well for me using both hard and soft  woods  sized from sticks to logs. BTW. if the R V has a basement could you convert it to a wine cellar?

regards Ian

[Frosty]

Yeah I've been playing with fire too long alright. Bars on edge to minimize contact with the burning material and maximize cooling and hopefully limit warping. While laying them flat makes it easier to get the over all length for least weight. I have to consider what Deb will be willing to move let alone lift in or out. Bars on the flat is still in the running.

Brazier, THAT's the term I've been blanking on! As brain planned so far it is an asymmetrical X, short legs for the feet. The idea isn't so much to keep "anything" from falling through or maximize the burn. It's so folk can sit around it at the RV campground, toast nibbles, stare into the fire while telling lies and not have to worry about a log rolling out and making them get up quickly.  

Using a couple chains as an adjustable stop is always a good fall back if the gate hook idea doesn't work like I think it should. 

I can't see your sketch Elements but I haven't massaged it yet. I'll make some sketches and see if I can figure out how to get Deb's printer to scan the things or just take a pic with my camera. 

1-1/2 thumb width spacing eh Ian?  Okay everybody likes the bars a lot closer than I was thinking, BTW my thumbs are about 1". 

I see I'm going to have to experiment a little and see what works. I can just adjust spacing with different length pipe spacers till I get what works. Then lock them in with the welded horizontals. Heck 1.2" sq. might be fine and I can twist it for a little fancy.

Stuff to think about, my ideas were getting stale. Thanks.

Frosty The Lucky.

 

[Glenn]

There seems to be a 

4 hours ago, Frosty said:

It's so folks can sit around it at the RV campground, toast nibbles, stare into the fire while telling lies

These are important details you have not mentioned before.

Coal grates for a fireplace (usually inside the house) are usually a basket type design with close spacing so the coal does not fall through the bars or casting.

 

Wood grates for the fireplace (usually inside the house) are usually wide spaced so the embers from the wood do fall through. 

You can build a wood grate and then lay a section of expanded metal plate over the grate which will give you support but a small opening for the ash, but not the embers, to fall through. If you keep the grate high enough, several inches, the grate or expanded metal should last a good while and not burn out.

One detail you have not addressed is the ash/embers falling onto the ground. Some locations do not appreciate the grass being burned, or a fire pit being dug into the ground. They strongly suggest (read insist) on a catch pan for the ash/embers.

 

Cue the 55 Forge (side blast forge with modifications)

The edge of a cut 55 gallon drum is sharp. Cut a 2 inch section from the circumference of the drum, fold it in half, and place it over the entire circumference of the sharp edge to keep from being injured. A couple of bolts (3-4) will hold it into place.

Cut 4-5 inches off the end of a 55 gallon drum and use it as both a fire pit and ash container. You can set it on some rocks, or make legs to keep it off the ground. IF you were to turn the design modifications team loose, it would not take long to come up with some really neat ideas. For instance, drive 3 short pieces (say 18-23 inches) of metal rod or stakes (say 1/2 inch diameter) into the ground. Each should have a loop on the top end. Weld 3 pieces of short chain to the outside of the drum pan and hang the drum pan from the 3 stakes with the chain. You now have a fire box, ash container, and up off the ground, all in one unit. The 23 inch length for the stakes is so it fits inside the drum pan for storage.

As the design modifications team has been turned loose, drive a longer piece of 1/2 inch diameter rod into the ground outside the drum. Construct a  say 12 inch ring with an expanded metal interior. Weld it to a say 1/2 inch rod. The other end of the rod will have a loop of 3 turns or so, that fits over the 1/2 long stake. This will form a friction fit and adjustable stop for the 12 inch ring. You can turn or rotate it about the long stake as close or as far away as you like, or raise it or lower it as you like. Sounds like a lot of trouble until you realize that you need someplace to put your coffee pot and or to keep your coffee warm. (grin) Or a simple shepard crook and S hook would do.  

There are visions of other wood fire pit designs coming to mind as the gears start turning and spinning up to full speed. So we need to remind the design modifications team that this is suppose to be portable, easy to set up and brake down, and weigh less than 100 pounds. 

[Tommytaptap]

Hi Frosty- Over this side of the pond, generally speaking I would, using a multi-fuel burner to burn wood; not use a fire grate at all. A grate holding other fuels like coal, charcoal etc. would need a grate to hold it up, to help circulate air to promote the fire and allow ash to drop through. 

Using wood of any sort as fuel, it is much better to allow it to sit on a flat solid bed of metal. (perhaps just a few small holes here and there to allow any water to drain through if left outdoors for any length of time) have the sides built up as far as you wish to hold the type of wood you will use. 

In the same way the a coal forge needs help from forced air to assist the fire-wood does not need anything else but the ambient air around it to burn successfully. In fact it burns better without a grate. There are thousands of ways you can do this and it is fair simply than constructing what you intend. 

For instance, here is a gas cylinder that has been modified albeit quite extensively but, it could be as simple as just cutting out a large enough hole in the side to accommodate your wood, a hole in the top for a chimney and some legs so as not to burn anything underneath it when in use.

The second image is a far simpler affair.

I just edited and included a third image which is the one I would go for. In fact, if you were to use a tall bottle, you could have a shelf in it around halfway up, solid steel welded in one, on which could sit your fire and the bottom half could be your 'wood store.' Just have a pull down side door to hold the wood/ash in until you open it to remove the ash!

[4elements]

i'll try again with the sketches

I noticed above you mentioned a pan to go under the grate and the folding V shape. The example Glen gave has a horizontal bottom which leaves a bed of coals in close proximity or contact with the wood above. The V won't allow that to the same degree. You could still get a folding design that would approximate the one Glen posted, it would just have 2 fold pivot points, and the end pieces could be extended a couple of inches to make legs. spaced at 3" it would be light and easy and with your pan under it set on folding legs you wouldn't run afoul of the burnt grass objectors.

[ThomasPowers]

Frosty; may I commend to your attention the search terms: fire basket images    

Lots of interesting stuff!

[Charles R. Stevens]

If you wer in farming country I would just grab a 24" disk, weld a patch on the center and make a trivet for it to set in, instant fire bowl... 

Or a big mixing bowl...