Can you supply a larger Findenser?

The additional weight and stress that a larger Findenser may place on a glass joint means that we currently have no plans to introduce a larger Findenser.

Can Findenser be repaired if it breaks?

Understandably, because Findenser is made of glass, people assume it will be easy to repair. Unfortunately, this is not the case. Why? The temperature Findenser would be exposed to during any glass repair procedure would compromise the sealants and lead to water leaks. It is also not practical or safe to disassemble Findenser to allow repair of the glass.

What is the chemical resistance of Findenser?

General guidance
Findenser is resistant to the majority of solvents and splash-resistant to dilute acids and alkalis at room temperature.  Extended exposure to acids or alkalis will attack the outer metal surface of the Findenser.  It is important to clean off any chemical spills immediately after they occur.
Further detail
The inner body of Findenser and the cone/socket, i.e. the wetted parts that come into contact with the substance being evaporated during normal use, are borosilicate glass 3.3, which has very good chemical resistance. (See TB 101 Glass Technical Data sheet available here for further details.) The metal finned jacket is anodised aluminium and the plug and seal are acetal and HT silicone. Please consider the chemical compatibility of your chemicals with these materials. You can consult chemical resistance tables online. It is not feasible for our R&D Laboratory to test Findenser with every possible chemical, so we cannot provide data. As well as wiping off any spills, ensure there is not a significant concentration of corrosive chemical vapours in the air around the Findenser (e.g. by using the Findenser within our guidelines, so the solvent is retained in the Findenser/flask). There is an advised cleaning protocol detailed in the FAQ entry, ‘Should I clean my Findenser? If yes, how?’

What is the optimum volume of solvent to be used in a flask with Findenser?

It is standard ‘good practice’ when heating solvents for a maximum of half the flask volume, e.g. 50 ml in a 100 ml flask, 1 litre in a 2 litre flask, to be used.  If a flask is over-filled, the condensation load on the Findenser may exceed its ability to cool and condense effectively.  In such circumstances Findenser will not contain the solvent.
  • Findenser: Maximum flask size 2 litres, maximum solvent volume 1 litre.
  • Findenser Mini: Maximum flask size 250 ml, maximum solvent volume 125 ml.

Will Findenser work in a warm lab?

Because Findenser uses air to cool and dissipate heat, it requires the ambient air temperature to be significantly cooler than the boiling temperature. At relatively high ambient temperatures, there may be insufficient air cooling for the heat from the Findenser fins to be effectively dissipated, which may result in Findenser not containing the solvent. However, the performance will depend on how different the ambient air temperature is from the boiling point temperature, so there should not be a problem with condensing high boiling point solvents. To maximise performance, ensure there is sufficient airflow around the Findenser to enable effective heat dissipation.

Can an inert gas flow be used with Findenser?

A flow of inert gas (e.g. nitrogen) through the flask will encourage evaporation and may reduce performance of the Findenser.  If inert gas is required it should be introduced through the top joint of the Findenser, with all flask ports sealed (using a suitable bubbler to avoid build-up of pressure) and not through a flask sidearm or joint at the bottom of the Findenser.  Gas flow should be kept to a minimum.

Can I use Findenser to condense diethyl ether?

Some very low boiling solvents are just too difficult to condense with any kind of air condenser. In such circumstances a water-cooled condenser may be the only option. Diethyl ether in particular is very difficult to condense. Findenser will cope with smaller volumes (up to 100 ml in a 250 ml flask) with a hotplate/heating block accurately controlled at no more than 5°C above boiling point.

Can you supply a Findenser with a B29 joint at both ends?

It is not possible to manufacture a Findenser with a B29 socket in addition to a B29 cone, as B29 would be too big for the outer metal fins section to fit over onto the glass body. If you need a B29 joint at both ends, order:
  • RR31102: Findenser B29 Cone, B24 Socket – 400 mm long
plus
  • RR139142: Enlarging Adapter Ordinary B24 to B29 (to fit in at the top, to enlarge the B24 socket to B29).

Is there any performance data for the Findenser Mini?

Our R&D laboratory carried out extensive testing of the Findenser Mini prior to its launch.  However, we haven’t currently published any data specific to the Findenser Mini. There is example data for the original, full-length Findenser in the Findenser leaflet.  The performance when using Findenser Mini with an appropriate volume will be similar to that given in the leaflet for the original, full-size Findenser, e.g. it is suitable for the same solvents. If you require any further information, please contact us.

What is the maximum solvent boiling point for use with Findenser?

Our R&D Laboratory have tested a wide range of common solvents, up to a boiling point of 155˚C. As we haven’t tested solvents with boiling points higher than 155˚C, we can’t make any guarantees that they would be suitable for Findenser, but we don’t foresee there to be any problems. It’s easier to condense high boiling point solvents than low boiling point solvents (as the higher the boiling point, the bigger the temperature difference between the vapour and room temperatures).  Therefore, performance with high boiling point solvents should be very good (and use with high boiling point solvents shouldn’t heat up the Findenser and weaken seals like you might expect).

What are B joints (B29, B24, B19 and B14 etc.)?

B joints are standard joint sizes in the UK and many other countries. The full names of these joints are B29/32, B24/29, B19/26, and B14/23.  The first number is the outer diameter (OD) in mm at the widest part of the ground glass cone, which is the same as the internal diameter (ID) in mm at the widest part of the ground glass socket (‘x’ in the diagram below).  The second number is the length of the ground glass joint in mm (‘y’ below).

Ground glass joint sizes

They have a standard taper (1:10 – for every 10 mm down the cone/socket, the diameter gets smaller by 1 mm). The ‘B’ differentiates them from American ‘A’ joints, which have the same maximum diameter and taper but are longer – e.g. A29 is A29/42, and A24 is A24/40. B joints are also sometimes referred to as ‘NS’ joints instead, so you may be familiar with that term – e.g. B29 (B29/32) is the same as NS 29/32, and B24 (B24/29) is the same as NS 24/29.

How can I improve the performance of my Findenser?

If your Findenser is struggling to contain all the solvent in your application, it is most likely due to one or more of the following issues. Please carefully review the following information, and adjust your method where appropriate, in order to obtain optimal performance from your Findenser.
Too much solvent
  • If a flask is too large or over-filled, the condensation load on the Findenser could exceed its ability to cool and condense effectively. In such circumstances, Findenser may not contain the solvent.
  • Working solvent volumes should be a maximum of half the flask volume, e.g. 5 ml in a 10 ml flask, or 1 L in a 2 L flask.
  • The maximum recommended solvent and flask volume for use with each type of Findenser is:
    • Standard (full-length) Findenser: maximum flask size 2 L, with maximum solvent volume 1 L
    • Findenser Mini: maximum flask size 250 ml, with maximum solvent volume 125 ml.
Overheating or poorly regulated heating
  • There is no benefit to the chemistry in overheating the solvent as the chemistry cannot get any hotter than the solvent boiling point, no matter how high the temperature.  Overheating will simply generate more vapour, which could be beyond Findenser’s capacity to condense.
  • The hotplate or block temperature should be no more than 20°C above solvent boiling point for high boiling point solvents (>80°C), or 10°C above boiling point for lower boiling point solvents (<80°C).
  • Where an oil bath is used, the hotplate or oil bath temperature should be no more than 10°C above the boiling point of solvent for high boiling point solvents (>80°C), or no more than 5°C above boiling point for lower boiling point solvents (<80°C).
  • In all cases, extra care should be taken if the heating control is not fully calibrated, or does not have precise settings.
Inert gas flow encouraging evaporation
  • A flow of inert gas (e.g. nitrogen) through the flask can encourage evaporation and reduce performance of the Findenser.
  • If inert gas is required it should be introduced through the top joint of the Findenser, with all flask ports sealed (using a suitable bubbler to avoid build-up of pressure) and not through a flask sidearm or joint at the bottom of the Findenser. Gas flow should be kept to a minimum.
Ambient temperature too similar to solvent boiling point temperature
  • Because Findenser uses air to cool and dissipate heat, it requires the ambient air temperature (room temperature) to be significantly cooler than the boiling temperature.
  • At relatively high ambient temperatures, there may be insufficient air cooling for the heat from the Findenser fins to be effectively dissipated, which may result in Findenser not containing the solvent.
  • The performance in each case will depend on how different the ambient air temperature is from the boiling point temperature, so there should not be a problem with condensing high boiling point solvents.
  • To maximise performance, keep the lab cool if possible, and ensure there is sufficient airflow around the Findenser to enable effective heat dissipation.
Very low boiling point solvent, e.g. diethyl ether
  • Some very low boiling solvents (particularly in large volumes) are just too difficult to condense with any kind of air condenser.  In such circumstances a water-cooled condenser may be the only option.
  • Findenser can cope with smaller volumes of diethyl ether (up to 100 ml in a 250 ml flask) with a hotplate / heating block accurately controlled at no more than 5°C above boiling point.

Can Findenser be stored at 0°C or lower?

Findenser should not be exposed to temperatures around/below 0˚C. Findenser is composed of an internal glass condenser and an external finned aluminium jacket, between which a small amount of water is permanently sealed (for heat transfer). Since water freezes at 0°C, if it gets cold enough the water inside Findenser could freeze – expand and cause internal damage to the Findenser. To prevent any risk of damage, please do not leave Findenser inside a vehicle if it may be exposed to freezing temperatures.

The Findenser literature says, ‘operating temperature range: 0°C to 60°C’. What does this mean?

This is referring to the environmental conditions of the whole Findenser unit, considering what the internal parts can withstand (so is not referring to chemistry applications / solvent boiling points etc.). You should not exceed 60°C when oven drying (or 50°C if cleaning in a dishwasher).  This is because high temperatures can weaken the seals etc., and lead to product damage/failure.
The minimum of 0°C is because the Findenser contains water (as heat transfer fluid) sealed in between the glass body and finned aluminium jacket.  If the Findenser gets cold enough, the water inside Findenser could freeze and expand.  To prevent any risk of internal damage, Findenser should not be exposed to freezing temperatures (e.g. left outside in a vehicle on a cold night).
For more information, please refer to the Findenser instructions and website FAQs.

Can you supply a Findenser without water sealed inside?

Findenser contains a small volume of encapsulated water, vital for effective heat transfer. The water in Findenser is sealed inside and cannot escape during normal use. However, we understand that your particular chemistry and safety guidelines may mean that the potential risk of water leaking from the Findenser (e.g. if the glass was broken somehow) is not acceptable. We don’t currently offer a standard Findenser with an alternative heat transfer medium in place of water. If you would like to enquire about whether we could manufacture a custom Findenser for you, please contact us with full details (quantity and proposed alternative heat transfer medium), and we will investigate.

Should I clean my Findenser? If yes, how?

The wetted parts of Findenser (the parts that come into contact with solvent during normal use, i.e. the inner body and the cone/socket) are made from borosilicate glass 3.3.  This has very good chemical resistance (see TB 101 Glass Technical Data sheet available here).  We would still recommend that chemicals are washed off, however. You should limit contact of the outer parts of Findenser with any corrosive chemicals you are using.  You should wash off any spills as soon as possible, and also ensure there is not a significant concentration of corrosive chemical vapours in the air around the Findenser. Our recommended Findenser cleaning procedure is:

  • Flush the internal glass surfaces with a suitable cleaning solvent such as acetone or IMS.  This is best achieved with a wash bottle.  External exposed glass surfaces may also be cleaned with a suitable solvent.  Allow washing solvent to drain into a suitable receptacle.
  • Wash the whole Findenser assembly in warm soapy water, using a soft brush to clean fins.
  • Rinse with warm water both internally and externally.
  • Allow to air dry.

If necessary, Findenser may be cleaned in a dishwasher; however, care must be taken to limit the temperature to 50˚C, or the plug/seal may be damaged.

Can I use vacuum with Findenser?

It depends on how you are intending to use vacuum.
Subjecting the whole Findenser unit to vacuum (e.g. placing it in a vacuum drying oven)
You should not do this – it could damage the Findenser seals.
Pulling a vacuum through the inner glass body of the Findenser before use
You can do this, for instance to dry the inside of the Findenser, or to remove air to replace with inert gas before an experiment. As the inner glass body is an open tube, the vacuum level achieved would depend on how you had it connected up (e.g. whether you made a good seal at each end, and which vacuum pump you used).
Pulling a vacuum through the inner glass body of the Findenser during use; use as a rotary evaporator condenser
This is not recommended. In rotary evaporators, vacuum is used to reduce the boiling point of the solvent, e.g. to 40°C. This would therefore reduce the temperature difference (delta T) between the chemical vapour temperature and ambient (air) temperature – and a good delta T is required for heat to effectively be dissipated out from Findenser.  Findenser would therefore not perform well, so is not suitable for this type of application. Furthermore, if you ran an experiment while you drew a vacuum up through the Findenser and out of the top, you would be pulling the generated chemical vapours up more quickly through the Findenser, reducing its performance; and if you connected the vacuum to a side arm, the chemical vapours would be drawn directly out the side arm, bypassing the Findenser.
Use of Findenser on the exhaust of a vacuum pump (e.g. of a rotary evaporator)
Findenser works well as a vacuum pump exhaust condenser – see our case study.
If you have too much solvent / the flask is over-filled, more vapour could be generated than the Findenser is able to condense effectively and so the Findenser may not contain all the solvent.  It is general good laboratory practice to fill flasks to a maximum of half full with solvent. 1 L solvent in a 2 L flask is the maximum volume our R&D Laboratory have tested, and so the maximum we can guarantee will work well. If you use the Findenser carefully (e.g. do not overheat the solvent) and have a relatively undemanding application (e.g. a high boiling point solvent, which is therefore easy to condense), then you may well be able to successfully use Findenser with a slightly larger solvent/flask volume, although we cannot make any guarantees.

Is Findenser compatible with US A joints?

While our standard Findensers have B joints, these have the same key diameters and taper as American A joints (it’s just that the A joints are slightly longer), so they are compatible. We have sold many Findensers in the US without issue, such as described in this case study. For more information on joint sizes, please see the FAQs entry, ‘What are B joints (B29, B24, B19 and B14 etc.)?’

Is Findenser suitable for use under pressure?

Pressure is not normally applicable to Findenser; it is typically used open to atmosphere at the top. If you would like to seal off Findenser (e.g. you want to stop air getting in and reacting with your chemicals), then you should use an oil bubbler or a chemistry balloon to prevent a build-up of pressure. Please be advised that the maximum pressure of all the glassware we manufacture is 0.5 bar above atmospheric pressure (also known as 0.5 barg, or 1.5 bar absolute pressure) – it should not be subjected to any significant pressure.