Sawdust Explosions

Back many years when I was probably in my early teens, we used to burn off our rubbish in a backyard fire (in a 40 gal drum repurposed as an incinerator).  Those were the days, taken that which could be burned and reducing it to ash, rather than having to carefully sort it into different bins to be put out on the naturestrip for the rubbish ‘police’ from the council paw through your bins in the dead of the night to ensure compliance with their inane rules.

One day, while we were burning off, I tool the full bag of fine sawdust from the beltsander and went to empty it into the fire. That resulted in an impressive fireball as I discovered how maximising the surface area , with a reasonable supply of air can result in quite a spectacular result.

The lesson has never been lost on me – sawdust can be a rather volatile substance.

So while watching part of my Father’s Day present I was amused to see the return of the sawdust cannon.

I am quite a Mythbusters fan, so have been working through the 5th season when I came across the viral video episode and was reminded of my early experiences with creating fireballs with nothing more than sawdust and an ignition source.

I’m not much of a believer of static sparks in dust extraction systems causing sparks/explosions, but still firmly understand the issues around disposal of a substance with such a significant surface area as fine sawdust.

Runnin’ Just to Stand Still

Lyrics by U2, reenactment by the entire planet these days it seems.  When did life get so busy?  Must be Christmas time again (and again and again – it’s almost like Groundhog Day).

Doing some rearrangement – trying out some different equipment layouts, primarily based around the new dust extractor.  Ran it for quite a while today (while it was still in the main shed), and although the noise is less than it seemed at midnight the other day, I still decided it would be better in the lower shed (the 3×3 that is next to the main workshop).  After clearing out all the pipework of the cholesterol that was building up (restricting the pipe diameter, and made up of heavy wood shavings, concrete dust, and who knows what else!), and particularly clearing some blockages where the original GMC dust extractor had not coped, and the pipe had blocked fully, I then got to try some different variations to see what worked better.

Firstly, different machines produce different types of dust & shavings (obviously). The jointer/planer and planer/thicknesser produces quite a long chip, that easily matts into a blockage, particularly given the rate that these machines shave the wood down.  Not sure what I will come up for these machines – difficult.  The shavings are also a problem even when they reach the dust extractor – more on that in a sec.

The tablesaw produces a much finer version, and a lot of dust, and given the much lower rate of production seems relatively easy to clear.  The bandsaw is even easier, primarily producing a fine dust.  The sanders are obvious, and easy.  The router table – finer than the tablesaw, coarser than the bandsaw, and although can produce a lot of particulate quickly (depending on how heavy a pass you are doing), a good flowrate will cope.

The real problem child, and who would have predicted this: the drill press.  Specifically when using a large diameter forstner bit.  The shavings are circular, and large (as large as the cutter’s internal diameter), and although they are pretty light and suck up ok, they are a distinct problem at the dust extractor.  Simply, they catch on the chip guards before the impellor, and almost immediately block the entire pipe.  Not dissimilar to one of the problems with the jointer, although that also has an issue with the shear quantity produced.

The solution for the jointer is easy enough – get a spiral head.  Unfortunately, the cost involved is very high, as nice as the finish can be from this type of cutter. Perhaps one day I’ll be able to bring you some first hand experience, but until then we will all have to look at this gold-plated solution with envy.  Otherwise, there is little option but to slow down!

For the forstner bits, the solution may have to be to turn the dust extractor off, and resort to dust pan and brush.

The next thing I looked at was flow rate at each of the machines.  It isn’t overly high, but that was the compromise – I can’t afford a 3HP machine – both the cost of the machine itself, as well as the power supply requirement.  So the 2Hp machine will have to do, and just accept the lower flow rate.  I tried it with my original 1st stage collector (documented here a few months ago), as that would have been ideal for the shavings collection before clogging the infeed to the extractor, but the flow rate dropped off way too much with that inline.  I might work further on that problem – perhaps a form of mini cyclone for the heaviest chips or something.  Pity – would have been good on a number of levels.

I also tried leaving off the pleated filter, so relying purely on the 1st stage chip collector, but there was little perceived difference in flowrate.  I guess this is a good thing – shows the pleated filter does not have too much of a detrimental effect on the dust extractor’s performance.

So that is about as far as I got – the pipes are cleared, the new extractor is sitting where the old one had been, and the infeed is connected directly to it.  Now all I need to do is work out some form of remote starter, so I can start and stop the extractor from the main shed.  It isn’t a matter of simply turning the power on or off, as the switch on the motor does not reengage when power is restored.  I might have to resort to a mechanical solution- a couple of long sticks through the shed wall!

Router Bit Maintenance

I’ve always considered that the real tool when routing is not the table, or the router, but the router bits.  It is the bits that make contact with the timber, and as the collection grows, it is the bits that make up the majority of the cost of a router / router table (although it takes some time to exceed the cost of an Incra fence if you head down that path!)

I haven’t had a chance to finish off the router storage cabinet – just another on a long list of jobs, and part of that is cleaning up the bits themselves.  There is quite an investment in them, so it makes sense to keep them in optimum condition.

The main issue I find with mine is they get quite a buildup of pitch and sawdust on the cutting surfaces, and that can’t make for an optimum cutting condition.  Some of my bits haven’t been cleaned for a while, and they were looking quite the worse for wear.  Unfortunately I didn’t think of photographing the worst one before I started.

Setting Up

Setting Up

Setting up to clean the Toy Train Track bits.  The bits are in a shallow tray, mainly to stop them rolling onto the concrete floor.  I’m sure there are better ways to transport bits around the shop, but that is what I have at the moment.  The other bowl is what I clean the bits in, and we have a cloth, an old toothbrush, Pitch Remover and Bit Lubricant.

Prior to Cleaning

Prior to Cleaning

This isn’t a particularly dirty bit, but it is the worst of the ones that I had when taking the photos!  You can see the pitch builds up to right near the tip of the bit, so I’d be very surprised if it doesn’t affect performance.  It would also cause the bit to heat up a lot more, but I don’t know if that is particularly detrimental to it, but it doesn’t sound like a good thing.

Application of Pitch Remover

Application of Pitch Remover

The Pitch Remover (from Carb-i-tool) is applied liberally over the bits (it’s also for saw blades etc).  I do this over the bowl which collects the excess – once I’ve finished with it, I can return the majority of the remover back to the bottle – no point wasting it!  Only a little that collects at the bottom which also has a majority of the removed pitch is thrown out.  Carb-i-tool also sells a container specifically for router bits, although this seems a reasonable alternative.

After Cleaning

After Cleaning

It doesn’t take much soaking time for the pitch & dust to be loosened, and the majority is removed with the toothbrush, which can get into all the corners etc, and isn’t going to damage the bit itself. the cloth is used to wipe the loosened pitch and the spray off.  The bits are them given a rinse in clean water and allowed to dry.

Bit Lubrication

Bit Lubrication

Next, I do a similar process with the router bit lubricant.  I don’t see why this would be particularly critical for non-bearinged bits, but it can’t hurt.  For bits with a bearing, this gets right into the bearings so they run smoothly. Normally bearings are sealed, but this isn’t always the case, and/or the seal can get damaged over time, so again it is a step that may or may not be particularly critical, but it can’t hurt.

Feeling loved once again

Feeling loved once again

The initial collection of bits after being treated.

Resurrection

Resurrection

This was my worst bit – used on a lot of pine on the Triton Introduction course, and had significant buildup.  Doesn’t look like it now, so it is back to being a bit happy (or is that a happy bit).

So that’s it – a quick job is all it takes to look after a significant asset.

Dust System Continued

Went shopping for more supplies for the ongoing dust system development. Ran into wall after wall unfortunately – to the point that I had to make some changes to the design. Bet woodworkers in the USA don’t have to change their designs just because 2.5″ blast gates don’t ‘exist’.

So here is the compromised design for the router table. It now has a single 4″ blast gate before the offtake to the fence. The length of tube leading to the fence may be a bit long, but I am not going to make that decision until I can actually fire up the system and make some serious dust to test the weaknesses. (I had the wrong lens for the camera tonight, so had to shoot it at an angle).

The other thing I purchased is a collector for the lathe. It is known as the Big Gulp, and I decided that getting the stand for an extra $60 odd wasn’t worth it. The normal intended orientation (I believe) is vertical, but I find the majority of dust I make on the lathe falls pretty much straight down. I’ll have to modify the final positioning, again when I have had a chance to test the system in anger. In this orientation, I think it should be called Deep Throat instead.

It is a pretty large collector – I’ve included my hand in the photo to give an idea of scale. That hole in the centre is 4″!

Dust Collection Options

As I recommission the shed, and the equipment within, I am paying quite a bit of attention to the whole issue of dust extraction and collection.  Even though I currently have a 1hp 4″ system that I plan on running to each machine, it just doesn’t seem to be enough.

I’m currently investigating the options, and am looking at the possibility of upgrading to a 2HP collector, and even including an air filter unit.

My ideal would be a cyclone collection, but the budget doesn’t stretch that far!  I might have to resort to the cheap-man’s cyclone option, rather than a specifically built all-in-one collector.  It’s all going to have to be manual blast gates as well for the same reason.

Tablesaw Engineering

I recently started a thread on a woodworking forum bemoaning the lack of good engineering on so many tablesaws out there.

To recap:

“Went for a bit of a tour of what sort of tablesaws were available out there. I haven’t covered the range by any stretch of the imagination, but I was quite surprised how …um…. average so many were.

I saw poor designs, shocking fences, ordinary guards, unwieldy splitters, poorly positioned power boxes (blocking components), and was rather uninspired. Some mitre gauges I saw I couldn’t believe existed – such crummy designs.

Overall, what the hell were the engineers / designers thinking???

I so wish the engineers that came up with the 2000 and all the decisions to optimise design while coping with the significant limitations imposed by working with folded steel had had a chance to have a crack at designing a decent saw table from the ground up. Perhaps that is the sort of thing that resulted in the SawStop. Pity I can’t afford one of them, because they at least look like they were designed properly. I’m sure there are other models out there as well that fit the bill, so I will have to ferret them out.

I mean, a cabinet saw is meant to be a major step up from a Triton WC2000, and I came away wondering why there are so many detractors of it. Ok, a solid top would be great, and a mitre slot an added bonus, but in terms of general functionality, is just the ability to angle the blade the only real gain?

Sure, I know that the solid (flat) top is significant etc etc, I mean, I do plan to get one (soon), but as I said at the start, I was rather dismayed just how many quite expensive table saws would still require me to turn a blind eye or accept compromises that I didn’t expect would be needed after moving up from a Triton.”

It did lead to a number of interesting comments and discussions, some of which directly reinforced my final choice of tablesaw.

It is perhaps then a little surprising (to me as well), that I ended up choosing a tablesaw that I had never actually seen, but such was the strength of argument. Forums are a great resource if you haven’t come across them before!

So I have been unpacking, and looking at the TS10L with a critical eye, and have thus far been very impressed. The build quality is superb, and as yet I haven’t been able to fault the machine (other than the instruction manual, but that is nothing new!) Even when it comes to placement of the switchbox, it doesn’t block any componentry and in fact as it has been placed on a corner which is not 90 degrees, you might expect them to shy away from that location – a bit complicated getting the angles right. Not so here, and that may seem such a minor thing to be impressed by, but it is small details like this that give you an idea that overall a lot of care and consideration has gone into the design and manufacture.

I still haven’t finished assembling the unit – been a bit busy with the shed itself, but I did manage to turn it on for a few seconds and cut some timber! This is not a commissioning of course – as is done in the Navy, you do tests and trials of a new ship before actually commissioning it into the fleet, so I am doing the same here! I think I am going to discover the pleasure of having a tablesaw again! I first found it when I got the Triton workcentre a number of years ago- a world of possibilities opened up, but over time I found that my enjoyment waned and I started not so much shying away from using the saw, but looking forward to other aspects of the project. Sizing the timber was not a stage I found myself enjoying anymore, and looked forward to having the timber cut ready for joining techniques on the router table, or prior to the saw – machining the raw stock.

In doing the couple of test cuts, I rediscovered something that I had forgotten existed – the pleasure of being able to accurately size timber for a project. Now this is not to criticise the Triton Workcentre, or its accuracy (which is still good for a well-tuned setup), but having a machine that you can still talk over while using it, that is HEAVY (yeah, contrary to popular belief, I like heavy machines!) and that has a good solid, flat top with real mitre slots actually tempts me to start new projects again.

I have been finding myself running the Incra 1000SE Mitre gauge up and down the slot just for the fact there is one that it fits, setting angles etc, looking forward to actually getting to use it! I haven’t done a rip as yet – still haven’t set up the rails or fence. (Haven’t even added the cast iron wings yet!) So as I stare into my crystal ball, I see a future with plenty of well cut sawdust approaching!

***Addendum*** I probably should add what annoys me most about poor engineering is in many cases there is only one of two things wrong.  Either a. ‘they’ have gone cheap, and taken a good (or at least reasonable) design and ruined it by using cheap, substandard materials when for a few cents more the right grade of steel/plastic/whatever would have resulted in a perfectly adequate machine (and not just tablesaws – this applies to everything manufactured).  Or b. (and the one that annoys me most) they have taken perfectly good material and ruined it by doing a substandard design.  Of course there is also c. substandard material with incompetent design which seems to be filling the shelves more and more recently.  There is also d. quality material coupled with inspired design which results in a product that is a pleasure to own and use.***

SSYTC002 Nostalgia – an early woodworking video!

SSYTC002 Nostalgia

Going though some old files, and came across this 7 second clip of a modification I made to the GMC thicknesser. Guess this actually qualifies as my first woodworking video (despite its short length).I’d forgotten the clip even existed!

Not sure of its vintage – probably 2004 – 2005. Not that long ago, and look how online video quality has improved

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