Introduction
This project is an extension of the Cheap and Efficient Mash Tun project also included on this website. That project described the use of a length of stainless-steel braided hose (removed from a sink faucet connector) connected to the spigot inside my beverage-cooler mash-tun as a cheap alternative to a false bottom. This worked surprisingly well, even with difficult cereal grain mashes. However, this sophisticated device often had a mind of its own and would curl up into the mash, compromising lautering efficiency. It finally met its demise when it got tangled up in a rotary stirrer I was using to mash-in some grains. Both the hose and the stirrer were totally mangled. Because this device had worked so well, I didn’t want to give up on the idea, so I designed and built a far superior mounting system for the braided stainless-steel hose.
Concept
This new device I have built is a holder for the hose, which keeps it in place at the bottom of the mash-tun to maximize mash efficiency and prevent it from becoming entangled in a stirrer. I’m calling it the Braided Spider because it has legs that stick out, and it looks a bit like a spider’s web. It’s very simple in concept – it has four splayed legs with holes in them through which a long-braided stainless-steel hose is threaded. The outer end of the hose is sealed with a plug, and the inner end connects to the mash-tun outlet spigot.
Designing the Braided Spider was fairly straightforward using the Autodesk Fusion CAD software, but making it proved to be a bit of a challenge. Using a 3D printer was the obvious choice for this, but the difficulty was in finding a suitable filament material to print with. This material would need to be strong, food safe, be able to withstand near-boiling water, and be impermeable to bacteria. Nylon or polypropylene would have been suitable filament materials, but they are pigs to print with (warping, stringing, delaminating, etc.). I found a source of not very well-known PCTG (Polycyclohexylenedimethylene Terephthalate Glycol-Modified) filament that appeared to meet all the requirements and was easy to print with – so that’s what I used.
I made two Braided Spiders – one for a 5-gallon beverage cooler (using a 6-foot hose) and the other for a 10-gallon version (using a 10-foot hose). The latter had to be printed in two parts because it was too big for my 3D printer. Although designed primarily for my beverage cooler-based mash-tuns, I think these devices would work with any other type and size of mash-tun. Further details on how to make one of these yourself can be found on my website[3]. The figures show my CAD designs, and the device being assembled and installed.
Materials Needed
Braided stainless steel hose:
6-ft x 12.0mm O.D. hose for refrigerator icemaker for 5-gallon mash tun
Or…
10-ft x 12.5mm O.D. hose for dishwasher for 10-gallon mash tun
Note that the icemaker hose has a slightly smaller diameter than the dishwasher hose. The holes in the printed spiders are set to match these. The thicker hose can be stretched to fit the smaller holes if necessary – or else the CAD design dimensions can be customised for a different-sized hose.
PCTG 3D printing filament
3/8” NPT bulkhead fitting
The washers aren’t used in the assembly.
1/2” stainless steel hose clamps
These single-ear clamps work well, but any other stainless steel clamp should also work.
6” x 3/8” x 5/8″ thick-walled silicone tubing
Only a few inches are needed.
Mash tun with spigot
Prepared as described here.
3D Printing the Spider
The Fusion 360 CAD files and the generated STL files are available for download using the link in the Assembly Resources section below.
Normally the user would just feed the STL files into their favorite slicing software to generate the gCode files the 3D printer needs to print the spider.
Three printable designs are provided:
- 160-mm leg span spider for a 5-gallon cooler
- 250-mm leg span spider for a 10-gallon cooler
- Two-part 250-mm leg span spider for 10-gallon cooler for smaller printers
Choose the appropriate design for your mash tun.
The Fusion 360 CAD files are provided for users who want a spider with different dimensions, allowing for customization.
The spider needs to be printed with a filament that is food safe, is fairly strong, and can withstand near-boiling water. It also needs to be printed in a way that helps prevent bacteria or other microbes from penetrating inside the printed part and breeding in there. The best filament I found for this purpose was PCTG from Best-Q available from Amazon – it meets these requirements and is easy to print. Alternatives would be polypropylene or nylon (polyamide) but they can pigs to print with.
I printed my braided spiders on my old modified Creality Ender 3 Pro 3D printer using the settings below. There were no problems occurring during the print and nice clean, and solid prints were obtained. There were a few minor wispy strings but these were easy to deal with.
Nozzle 0.4 mm Brass
Initial Layer Height 0.2 mm
Layer Height 0.12 mm
Line Width: 0.6mm
Wall Count: 3
Top/Bottom Count: 9
Infill: 50% Cubic
Print Temperature: 260 °C
Initial Layer Temperature: 260°C
Build Plate: Textured PEI at 90°C
Print Speed: 35 mm/s
Cooling Fan: Off
Adhesion: Skirt
Assembling the Spider
In the first instance, install the 3/8” barb bulkhead fitting into the center of the spider. If you have printed a two-piece spider because your printer isn’t big enough for the single-piece part, the bulkhead union will hold the two halves together as shown. There are some raised pillars on the mating surfaces that will stop the two halves from rotating against each other.
The holes in the spider for the braided hose are arranged as a spiral. Find the outermost hole and start threading the braided hose clockwise from there. Push a few inches of hose in at a time and coax it through successive holes in the spiral. The braided hose has some stretchiness to it so there’s some flexibility as to how many holes the hose will thread through. It doesn’t matter if there are unused holes in the inside of the spiral. End the threading when the outer end of the hose is close to the outermost hole and the innermost end is in a position for easy connection to the bulkhead fitting. Don’t stretch the hose too much or its diameter may become too small and the hose will be loosely mounted.
When the inner end of the hose is close to the bulkhead union, thread a hose clamp onto the hose.
Push the plug into the first (outermost) hole in the spider. The outer end of the hose should be within easy reach. Thread a hose clamp onto the end of the hose.
Secure the outer end of the hose onto the plug with the clamp.
Secure the inner end of the hose to the bulkhead fitting with the clamp.
Push a length of 3/8″ thick-walled silicone tubing onto the remaining barb on the bulkhead fitting.
Trim the length of the silicone tubing so that it’s the right length to connect to the barb fitting on the outlet spigot. It’s probably best to do this with the spider in the mash tun.
Connect the silicone tubing to the spigot barb.
Installation is now complete.
Remove the spider and inspect it carefully. Remove any bits of plastic, dust, insects, etc. and give the assembly a good wash with hot soapy water. It would be a good idea to put it in a dishwasher to clean – the plastic used in the printing can withstand dishwasher temperatures.
Finally, place the spider into the mash tun and make sure it sits well on the bottom. Reconnect the silicone tubing between the barbs on the center bulkhead fitting and the spigot.
Now brew some beer!
Top^.
Using the Spider
Follow the instructions given in the mash tun assembly webpages. In use, it blew away my expectations. My mashes became much more efficient, and I was typically seeing 85 to 90% extraction – even with heavy mashes. The last runnings usually got down to a SG of 1.003, indicating efficient lautering. I was able to brew an award-winning hefeweizen[4] with 76% wheat malt in the mash and get crystal clear wort without any need for rice hulls. Also, I’m now safe in using a powered stirrer because the braided hose now keeps itself out of the way.
I think this type of filter works better than a false bottom for several reasons:
- The effective filter area of a 10-foot braided hose (1283 cm2) is much greater than for an 11½ diameter false bottom (670cm2).
- The braiding provides a much finer filter mesh and is multi-layered.
- The wort enters the hose from all sides so that it is not so affected by grain bed compression from the top like it would with a false bottom.
- The edges of a false bottom may not be perfectly sealed against the bottom of the mash-tun, especially if moved by stirring, which may allow grains to exit with the wort and possibly cause blockage. It would be impossible for any grains to enter the braided hose and exit with the wort.
- It should be cheaper.
Licensing
This project is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
This license means that the information on this website for this project is free to download and use for non-commercial purposes. If any content or derivation of that content is published, then an acknowledgement should be included referencing the original developer – me (Andy Tipler).
If you want to make money out of my efforts, please contact me via the email address at the base of this page for an initial discussion .
Assembly Resources
The following downloadable resource file contains details on how to build your own Braided Spider:
- STL file for 3D printing the smaller spider for a 5-gallon mash tun.
- STL file for 3D printing the 5-gallon plug.
- STL file for 3D printing the larger one-piece spider for a 10-gallon mash tun.
- STL file for 3D printing the larger two-piece spider for a 10-gallon mash tun. Both halves are the same.
- STL file for 3D printing the 10-gallon plug
- Fusion 360 modifiable CAD files containing the original designs enable custom sizes.
This information is provided completely free for non-commercial use. However, it does cost me money to make and test these devices and to maintain this website. If you would like to further encourage me in this activity, please consider making a donation below – your support will be much appreciated.
Final Thoughts
I have now built a few of these braided spider devices. – they really do work well and are easy to use. The biggest challenge was finding a suitable filament for the 3D prints. The PCTG filament I used is rather unique and it’s difficult to recommend an alternative for this purpose.
If you make one of these, I hope you find that it works well for you. If it does, let me know. If it doesn’t, well, have a nice day!