Heat proof mat to protect underside of shelf from air station? - Page 1
Forum section: electronics / general

author: HobGoblyn
author_rank: Unknown
timestamp: February 25, 2020, 02:33:53 pm
content: This has got me stumped.Moving everything around, I have my air station in the perfect place. (Ignore the cables at the back, these will be moved before I finish)But I need something to protect the underside of the shelf above, while the air station is cooling down (pushes air at full power when placed in stand until temp is 100 C)All I really want is a 15cm (6") square, (around 5mm/1/4" thick) of hear resistant whatever that I can screw/glue to the underside of the shelf.Finding such a thing is harder than I thought.I could use a bit of a silicone mat, but I doubt there's any glue that will stick it to the wood, I suppose I could use screws, but I suspect it will sag.I could use something like a plumbers solder mat, but that will not last a long time.All suggestions greatly appreciated.Many thanks

author: nfmax
author_rank: Super Contributor
timestamp: February 25, 2020, 03:40:20 pm
content: A ceramic tile, maybe? Or some stainless steel sheet?

author: Gregg
author_rank: Super Contributor
timestamp: February 25, 2020, 05:25:39 pm
content: All that is needed is a heat shield. The key to a good heat shield is air circulation behind it.Some aluminum spaced about 10mm from the bottom of the shelf so that air can circulate. The baking department of a local store should have small one use pans that would suffice or you could use any sheet aluminum and make some stand offs out of whatever you might have around.

author: HobGoblyn
author_rank: Unknown
timestamp: February 25, 2020, 06:55:53 pm
content: Quote from: Gregg on February 25, 2020, 05:25:39 pmThanks. Does the thickness matter, can get a 20cm x 20cm sheet from 1mm right up to 10mm thick.

author: Ian.M
author_rank: Super Contributor
timestamp: February 25, 2020, 08:01:33 pm
content: Any aluminium sheet thick enough to hold its shape would be fine. Ideally, the top surface should be polished for minimum IR emissivity, and I would recommend using fibre washers either side of the sheet at the mounting holes to minimise heat conduction to the screws. If there's any chance of a 'runaway', aluminum foil stuck on the underside of the shelf, shiny side out, using heat resistant adhesive, will minimise the heat transfer to the shelf if the shield itself becomes dangerously hot.

author: Gregg
author_rank: Super Contributor
timestamp: February 25, 2020, 09:58:13 pm
content: Thickness is not a problem but thicker aluminum will spread the heat more quickly over the entire surface potentially giving a smaller delta T between the shield and the shelf.Small stand offs can easily be made with some metal or PTFE tubing with long enough screws to fasten the heat shield

author: richnormand
author_rank: Unknown
timestamp: February 26, 2020, 12:32:38 am
content: I assume your heat nozzle is like mine in that it will shoot hot air for while after use to eventually cool air to lower the nozzle temperature quickly after use. Not exhaust the full hot air continuously.Two ways I dealt with similar problems in the workshop and kitchen.1)Workshop.a 30x30 cm aluminium metal sheet placed about 1/2 cm with standoff away from the wood to allow good air current. It would carry the heat to all its surface and although hot at the source of heat the surface temperature behind was barely warm.Of course this was for reasonably short time periods (<10min) for occasional propane torch welding.2)in the kitchen in a nook with a large toaster. The inside at the top was getting pretty warm and peeling the top covering. I used a product to heatshield high temperatures for cars (left over from turbo installation).It is flexible and has an aluminium top, a middle made of compressed fiberglass (about 2mm) and coated with 3M adhesive tape on the back. It was available in rolls or large sheets. Been there for over 15 years now and in perfect condition.Solution #2 is the easiest. Just peel and stick to the surface. Good for several hundreds of degrees.

author: amyk
author_rank: Super Contributor
timestamp: February 26, 2020, 01:33:10 am
content: Take a piece of wood the same as the shelf, aim the hot air at it from roughly the same distance and see how long it takes before something happens, or you get bored.You may be pleasantly surprised.

author: HobGoblyn
author_rank: Unknown
timestamp: February 26, 2020, 01:59:25 pm
content: Quote from: richnormand on February 26, 2020, 12:32:38 amI would have gone with this if only I had read it about 1hr earlierAs it is, I bought a sheet of aluminium and fixed it leaving a 9mm gap and with fibre washers either side of the screws as per Gregg's and Ian.m's suggestions.Many thanks everyone

author: Gregg
author_rank: Super Contributor
timestamp: February 26, 2020, 09:18:31 pm
content: Looks goodI'm all for using materials that you already have or whatever is as easy and inexpensive as possibleYou may want to add a lip on the back to protect the back wall if it becomes a problem.

author: Hydron
author_rank: Super Contributor
timestamp: February 27, 2020, 03:59:47 pm
content: I was worried about the exact same thing (albeit with a slightly bigger gap to the shelf), but some careful testing showed that the heating of the shelf during cool down was only minor. In the end I didn't put any protection on the shelf, but thanks for the stick on insulation suggestion - will keep it in mind for the future.

author: unknownparticle
author_rank: Frequent Contributor
timestamp: March 15, 2020, 09:26:22 pm
content: If anyone else needs something for similar purposes there is a purpose made material that is used for heat shielding in the engine bay of modified cars, this is one supplier :-https://www.ebay.co.uk/itm/G1-GI-Lite-Embossed-Aluminium-Heat-Shield-Material-300mm-x-400mm-Sheet-Exclusive/311999804495?hash=item48a4a3344f:m:mSasB8x_keqr9k8Muzp67uAIt is supplied as a sheet and can be formed as required. There are probably many suppliers in various parts of the world at different prices. It works extremely well though, I know from experience as I use it to shield the turbo from sensitive parts on my car.

author: coppercone2
author_rank: Super Contributor
timestamp: April 06, 2020, 03:50:22 am
content: what you can also do is make some kind of heat vent on top so it directs the hot air to a suitable heat sink (and test it on full blast to make sure nothing melts. Would help if you move the station some where. When I really think about it, I am surprised it does not come with it as a feature (I Hate hot air). Always felt some how the tool was made to look good. Even a soldering iron tends to not burn surfaces if you set it down since the cord is usually nimble and it has a guard on it. Hot air can just invisibly start fires.. like the hakko iron is weighed so it naturally elevates the tip, so long you don't shove it into a pile of paperwork it seems OK. It seems particularly insidious as a standard benchtop tool. I wonder what it would look like if it actually had a safe port diffuser thing for the hot air to go into and spread out enough to not burn anything.