The Lemon Fool

I have a garden pressure sprayer similar to:

https://www.ebay.co.uk/itm/TUKAN-Druckspruhgerat-5-Liter-mit-verstellbarer-Duse/223499836801?epid=1542127014&hash=item3409a0dd81:g:424AAOSwfYBcfvIX

A small pin-hole leak has developed in the centre of the seam across the base. The material of the container is only described as "high quality plastic" and the unit is no longer under guarantee. The area of the leak is not particularly flat due to the seam otherwise some solution using a small bolt/nut/washers might be effective. There is also a danger of the seam splitting further.

Any ideas how best to attempt a DIY repair?

Can you get inside the vessel or can you only access the outside? If you can get inside could a blob of silicone sealant work? If you can only get to the outside if the plastic is of the thermoplastic type and thick enough I'd consider heating and smearing with a soldering iron? Epoxy putty is another good sealer of water I've used to mend a hole in Liza's bucket

kempiejon wrote:Can you get inside the vessel or can you only access the outside? If you can get inside could a blob of silicone sealant work? If you can only get to the outside if the plastic is of the thermoplastic type and thick enough I'd consider heating and smearing with a soldering iron?

Assuming that this is indeed a thermoplastic, a hot glue gun repair will withstand a lot of pressure, and the risk of rupturing the plastic is less severe than the soldering iron approach. But the "wound" needs to be very clean and dry before you start.

Then again, these things are as cheap as chips: https://www.amazon.co.uk/Spear-Jackson- ... 00RD0KTZQ/ Worth one repair attempt, not two.

BJ

I would try putting a small self tapping screw through the hole.

pendas wrote:I would try putting a small self tapping screw through the hole.

Not as crazy as it sounds. I know a plumber who did that with a copper central heating pipe after he holed it with a nail. (In his own CH system, not a customer's.)

It's still holding after eight years. I wish him luck. To say nothing of his neighbours downstairs...

BJ

Won't the different metals cause corrosion to acce!erate in the system ?

There should be a symbol somewhere on the container (probably on the bottom) to say what it is made of,
https://www.pstt-cpd.org.uk/ext/cpd/pri ... g-symbols/

The container will be made of a thermoplastic which cannot easily be glued. Ideally, a small hot air gun of the type used for plastics welding or for desoldering could be used to weld the hole shut. Any filler rod must be of the same plastic as the container. Personally, I would probably try this for the pleasure and satisfaction of effecting a repair rather than as a cost/time effective excercise.

Alternatively, there is the "pot mender" approach which you mention (bolt/nut/washers). You say that the seam is not particularly flat but would something like a tap washer take up the difference? Make sure that the bolt is a snug fit in the rubber washer.


Julian F. G. W.

bungeejumper wrote:Not as crazy as it sounds. I know a plumber who did that with a copper central heating pipe after he holed it with a nail. (In his own CH system, not a customer's.)

It's still holding after eight years. I wish him luck. To say nothing of his neighbours downstairs...

richlist wrote:Won't the different metals cause corrosion to acce!erate in the system ?

If it was a steel screw, it will now comprise mostly of rust. Stainless steel will cause corrosion of the copper which is why a copper immersion heater (or any other immersion heater with a copper thermostat pocket) must not be fitted to a stainless hot water cylinder. Either way, I consider this a ticking time bomb.


Julian F. G. W.

Since it's only a small hole, I wonder if giving the inside a good clean, letting it thoroughly dry, then pouring in a few mm of something like evostick, PVA glue, silicone sealant or whatever might work. So instead of focussing on the hole, create a barrier across the whole of the base. Having the seal inside means that any pressure will tend to improve the seal.

--kiloran

Thanks for all the suggestions - what a great facility TLF is!

I see reviews on Amazon which confirm that this is far from a rare problem with this sprayer - there is even a photograph.
A repair would definitely be in the category of self-satisfaction rather than of cost saving.

The manufacturer appears to be German: GLORIA HAUS- & GARTENGERAETE GMBH. They produce a range of pressure sprayers under the names of Gloria and Tukan. I would be hesitant to buy similar again - a pity when the unit was otherwise of decent quality and quite satisfactory in use.

The letters "PE" appear on the base which suggests either polythene or polyethylene (high or low density not apparent) - I think a thermoplastic rather than a thermoset. Very difficult for anything to stick to this plastic but I tend to favour a repair attempt using silicon rubber on the inside as suggested. The pin-hole is due to the seam splitting so a screw is only likely to make things worse. Access is limited but possible - neck 4.5 cm diameter, height 40 cm. The main difficulty is likely to be in first cleaning the inside (had been used for weedkiller).

paradigm

paradigm wrote:The letters "PE" appear on the base which suggests either polythene or polyethylene (high or low density not apparent)

Polythene, polyethene and polyethylene are differrent names for the same thing. I would expect PE to be low density polythene, although it is sometimes abbreviated to LDPE. If you are welding it, I believe that LDPE filler rod is ok to use on LDPE, MDPE and HDPE; and MDPE filler rod is ok for both MDPE and HDPE. HDPE filler rod can only be used on HDPE. It is probably like being able to use brazing alloy to join steel but not steel welding rod to join, for example, bronze.

Julian F. G. W.

Thanks for the information Julian.

You have encouraged me to maybe attempt a plastic weld! Looking at the leaking seam more closely it may be that a filler rod of some kind has already been applied, perhaps during remedial work in manufacture. Unfortunately, for access, the repair would have to be done from the outside rather than the inside.

Filler rods are new to me and I cannot immediately identify a source. I wonder if a strip cut from a scrap LDPE container could be used? I see that the melting temperature of LDPE is 120-180 deg C. I have soldering irons and a hot air gun - an iron is liable to be too hot and the gun not localised enough (could use a mask/shield) - all sounds rather tricky!

paradigm

The DIY force is strong in this one. Impressed. C.

Yep! Some people do crosswords, others............

paradigm wrote:I have soldering irons and a hot air gun - an iron is liable to be too hot and the gun not localised enough (could use a mask/shield) - all sounds rather tricky!

The hot air gun will just deform the bottle. Indeed, that's one of the odd things that they're useful for.

When my wife's plastic bumper got a deep dent along the side from an inconsiderate parker, the hot air gun eased it right back out again without my needing to physically touch it at all. (There's a technique for that - YouTube is your friend.) Similarly, when I drove my car over the hollow thermoplastic foot of my granddaughter's play slide and completely flattened it, the hot air gun coaxed it fully back to shape.

I'd still say that the glue gun (or rod) is your best bet. You can buy hot melt sticks in various grades for various uses - but don't spend too much. This is a cheap item you're repairing, after all.

BJ

Thanks

Correction to earlier

Melting points:
LDPE - 105 - 115 deg C
HDPE - 120 - 180 deg C

paradigm

paradigm wrote:Filler rods are new to me and I cannot immediately identify a source. I wonder if a strip cut from a scrap LDPE container could be used? I see that the melting temperature of LDPE is 120-180 deg C. I have soldering irons and a hot air gun - an iron is liable to be too hot and the gun not localised enough (could use a mask/shield) - all sounds rather tricky!

An eBay search for "ldpe welding rods" brings up some hits. A scrap cut from an LDPE container should work fine. The important thing is that it is the same type of plastic.

The type of hot air gun needed can be fitted with one of a range of small nozzles and can provide the localised heat needed for welding. Googling "Plastic welding gun" brings up some examples. A soldering iron might work if you can keep the temperature hot enough to melt the plastic but not enough to burn it.

If you use a glue gun, do a bit of research into the type of glue stick you need. It would need to be compatible with polythene and be waterproof. I would be surprised if it gave a long-term fix, especially if you used just any glue stick you had lying around. I am not a big user of hot glue, however, so my gut feeling that it would not be very effective might be wrong.

Julian F. G. W.

Rather than buying a filler stick you could shave a small amount of plastic off the rim of the spray bottle (i.e. the bit hidden by the cap when it is screwed on.

Heat the area with the hole up, but not too much, maybe use a piece of wood or metal sheet with a hole cut in it to shield most of the surrounding area, at the same time heat up the scraps of plastic on a spatula/knife until they are melting and then apply. Continue t apply heat until you can smooth the filled area over. I fixed a wheelie bin used as a water butt this way.

However give that it is a seam that is leaking, If it is on a flat area I would be more tempted to drill out the hole and use a nut, bolt and some steel and rubber washers. But if it's on a ridge then it'd be the heat option.

BH