Bubble Jet Cartridges - Is it Safe to Refill

Almost all the economy priced computer printers these days are bubble-jet types.
They are quite cheap to buy, but most of us shudder when we see the price of replacement cartridges.
As an alternative you can buy ink kits to refill your used cartridge, or send the empty cartridge to one of the many cartridge reconditioning firms now in business.
But what about the horror stories that circulate:- is it true that refilled cartridges can wreck your printer and void the warranty? Do they make a horrible mess and give poor results?
Like most popular stories there's some truth behind these claims, and also quite a lot of misunderstanding. Common sense is a good guide in deciding whether it's a good idea to use refilled cartridges in your printer:-
For printers with a permanent print head
Some printers have a permanent print head - an array of tiny nozzles which passes back and forth close to the paper and creates the printed image. When you replace the cartridge on one of these printers you're simply replacing a small tank of ink. And you don't need to be a rocket scientist to realise that if you put in a tank of incompatible ink you may clog up the print head and be in for a costly repair.
If I owned a printer of this type I would use only genuine original printer cartridges, and avoid the risk of refilled cartridges.
How can you tell if your printer has a permanent print head?
Examine the cartridge. If it looks like a simple plastic box, and its bottom edge is not immediately next to the paper surface when it's fitted in the printer, you probably have a permanent print head. I believe most (if not all) Epson printers are of this type.
For printers with a disposable print head
This type of printer has the print head built into the cartridge. When you buy a new cartridge you get a new print head. You can recognise this type of cartridge fairly easily when it's fitted in the printer because it's lower edge will be very close to the paper (necessary, because it squirts ink onto the paper), and you will probably be able to see a cluster of metal contacts on one side of the cartridge (sometimes partly hidden inside a slot).
With a disposable print head there's very little risk in using refilled cartridges. If for some reason an unsuitable ink is used and the print head is damaged, there's no great loss as you would have thrown it away anyhow if your hadn't refilled it.
Many Canon and Hewlett Packard printers have been produced with disposable print head cartridges, though you can't take this for granted as there are many different models.
Some Canon printers have a permanent print head fitted inside a removable assembly which you can take out by releasing a small lever. The assembly has replaceable ink tanks and, if you were to use the wrong ink and damage the print head, you would need to buy a new assembly. Fortunately you can easily fit the new assembly yourself and its cost is not huge.
Our printer at SeniorNet has this system. The assembly is used for black and colour printing and can be quickly removed and replaced by a large disposable black cartridge, (which is used most of the time for black only printing as the cost per page is lower).
What about Warranty?
Many printer manufacturers try to discourage their customers from using cheaper cartridges by having a disclaimer on their warranty. However, in New Zealand the manufacturer's warranty for a printer is not necessarily important, as the Consumer Guarantees Act protects the user and makes the retailer responsible for dealing with problems arising from faulty equipment.
If your printer breaks down the retailer cannot refuse to fix it just because you've been using refilled cartridges; it doesn't matter what the manufacturer's warranty says. He would need to show that you probably caused the breakdown by using and unsuitable ink or cartridges.
Logically there should be very little risk of this if your printer has disposable print head cartridges, as it's unlikely that refilling these would damage the printer.
Do-it-yourself refill kits
Shops which sell printer cartridges often sell refill kits. If you are tempted to try your own refilling, here's some advice:-
1) Always read the instructions on the kit (before you start the job) and follow them carefully. If you make a mess you probably haven't followed the instructions.
2) Refill the cartridge before it is completely empty.
When a cartridge runs out of ink and stops printing it probably will have entrapped air inside the bubble jet chambers. If you can avoid this you should be able to keep refilling cartridges without trouble. If a cartridge does run out and you want to refill it, do it immediately (or put it inside a sealed plastic bag with some damp paper until you can refill it).
How do you know when to fill?
If you haven't got a crystal ball you need some other way of knowing when a cartridge is nearly empty. I just weigh my printer cartridge, using a set of electronic kitchen scales which will weigh in 2 gram increments. (This could be a good excuse to buy some new kitchen scales)
When there's less than 5 grams of ink remaining, I top the cartridge up. It only takes a few minutes.
3) Don't overfill.
Many cartridges have some kind of absorbent material inside, to hold the ink. If you put in more ink than this material can hold, it upsets the rate of ink flow and you may find the cartridge makes messy blobs instead of printing. (This is perhaps one way you could damage the printer if the ink gets in the wrong place).
To decide how much to put in you could weigh the next new cartridge you purchase (once you have removed the protective packaging etc) and mark the weight on the cartridge. Weigh it again as soon as it's empty and write this down too. Then refill immediately and make sure you put in about 5 grams less ink than needed to bring the cartridge back up to its original weight. If you use a syringe and hypodermic, remember that 1 cc weighs 1 gram.
My old Canon printer had been using refilled cartridges for seven years and is still going well. With the right methods, refilling is quick and easy, and has saved me hundreds of dollars. However, if you're careless or take shortcuts you can make a mess. I know!

John Selby (technical bloke).

First printed in SNN Newsletter August 2001 and again in September 2002