Polyurethane Adhesive – help please

[Danni BurnsParticipant @danniburns84841]

Hi all

I admit to knowing nothing about many topics, and chemistry is one of them.

I have a WaterRower (rowing) machine and the water tank periodically needs resealing. I’ve done it once and it’s that time again. WaterRower is charging £75 +PP to sell a 2-pack adhesive for this.

Many forums (mainly USA) since during Covid have discussed this, as there appears to be a shortage of the adhesive.

They recommend: Loctite UK U-09FL and  Araldite 2028 (and maybe Pattex Power Epoxy Welder, and Mannol 9904 Epoxy) as equivalent, but these are not readily available in the UK (that I can find), other more outlandish suggestions are B-7000 Glue, Window Silicon, Gorilla tape, etc.

The nearest I can find is: Power Mix 2K Polyurethane Universal Repair (available on eBay)

My understanding is that I need a Polyurethane Adhesive and better if it’s Two-Part for curing speed (but not essential for me) and not an Acrylic Solvent Cement (which will bond permanently). I may need to open it again!

I need some assistance in identifying a UK available product that matches the spec at the attached link:

http://www.protavicamerica.com/pdf/TDS%20PNU-46202%20REV%203.2.pdf

I have extracted/pasted the basic details below:

DEFINITION
PNU-46202™ is an electronics grade; unfilled, room temperature fast curing; two-component polyurethane adhesive is designed for the adhesion and encapsulation of circuit boards, circuit board components and for screw-thread sealing. The cured materials provide long-term circuit protection and bond stability from -55C to 100C. PNU-46202™ bonds well to most metals, ceramics and plastics as well as to epoxy and paper phenolic circuit boards. The clarity of PNU-46202™ allows examination of all encapsulated components and circuit boards. PNU-46202™ is available in self-mixing MixPac ® for field use and in plant applications.

PRODUCT DESCRIPTION
Appearance – Liquid
Odor – Faint
Color (May be modified to meet you requirements) – WATER CLEAR (& colors)

Property – Result – Methods
Viscosity – 8,000 mPa·s – Brookfield RVT, Spindle 27, Small Sample Adaptor, 10 rpm, 25°C

Other information
Work life time @ 25 ± 2ºC = 5 minutes

Regards

Danni

[bernard towersParticipant @bernardtowers37738]

Good job cylinder head gaskets are not made like this!!!!

[JasonBModerator @jasonb]

If you put PU Potting Compound into google you will get some similar products.

Without knowing what the tank is made from hard to know what will stick it.

[Danni BurnsParticipant @danniburns84841]

Jason

Here is a link to a WaterRower:

https://www.waterrower.co.uk/shop/waterrower

This is the tank to be glued:

https://www.waterrower.co.uk/wrpt004-clutch-tank-assembly-without-clutch

Does that help?

Regards

Danni

[Michael GilliganParticipant @michaelgilligan61133]

If you don’t mind me saying so, Danni

… I think the price of the Allen key is a good indication of their game

.

.

 

Sorry, I’m still not sure about the constructional details of the tank [“two halves”]

?

MichaelG.

.

Edit: __ In your position, I would be inclined to ask these people for a recommendation:

https://www.thegluepeople.co.uk/polyurethanes-c-6_10/

 

[Danni BurnsParticipant @danniburns84841]

Agreed.

Its like a kinder egg. Has an interlocking lip on each half.

Thanks for the suggestion. Will email them now.

[Grindstone CowboyParticipant @grindstonecowboy]

If it has some mechanical means of being held in position i.e. the glue isn’t the only thing stopping it falling apart, then probably CT1 would do it.

Rob

Links to https://www.ct1.com/our-products/ct1/

[Danni BurnsParticipant @danniburns84841]

Thanks Rob

I recognize CT1 from when sealing some lead flashing underneath window sills. That is very thick and tacky stuff.

Yeh I think it probably would do the job. I’ve looked at the Spec sheets and it doesn’t tell me anything helpful.

How long to cure, how thick bead is needed, etc.

Actually, I think some of the Silicons would do the job. I’ll look at ‘other’ options later.

Still hoping someone can decipher that PNU-46202 Spec and advise of a same product.

Cheers

[Michael Gilligan]

On Michael Gilligan Said:

If you don’t mind me saying so, Danni

… I think the price of the Allen key is a good indication of their game

.

 

 

MichaelG.

 

And that price is for a key to tighten Allen screws, they probably want another fiver for a key to loosen them!

Ian P

 

[ChrisLHParticipant @chrislh]

I’ve used Gold Label Underwater pond sealer for just that and it’s still going strong and flexible after 7 years under water. £20 ish, very sticky but black so likely a messy looking job.

[Danni Burns]

On 11 April 2024 at 11:31 Danni Burns Said:

Hi all

I have a WaterRower (rowing) machine and the water tank periodically needs resealing. I’ve done it once and it’s that time again. WaterRower is charging £75 +PP to sell a 2-pack adhesive for this.

 

Many forums (mainly USA) since during Covid have discussed this, as there appears to be a shortage of the adhesive.

 

Regards

Danni

I feel something is amiss here.

Surely if a product requires occasional resealing I would expect that it should be done with and easily replaceable sealant or gasket (an O-ring even!), advising the purchaser to use an adhesive is asking for trouble. The enclosure appears to be an acrylic or polycarbonate moulding so I would expect that removing old adhesive to prepare the surfaces for resealing would be a rather time consuming and difficult task, maybe with not always a good outcome.

Permanently bonding the two halves together 100% leak free, could be done with structural Methacrylate adhesive as used to assemble carbon fibre and metal bicycle frames. Since there appears to be a rotating shaft passing through a seal then presumably the design requires the unit to be dismantled for servicing but I would not have expected that an adhesive would be involved.

Ian P

 

[Dick HParticipant @dickh]

We´ve been here before. I remember answering a similar question several years ago but this site being what it is I can´t  find it.

[Dick HParticipant @dickh]

PS:- Using a methacrylate adhesive may cause problems with the adhesive attacking the material the part is made of. methacrylate adhesives are typically a solution of a polymethylmethylacrylate in solvent (acetone) or a polymerisable oligomer in methyl methacrylate which can be UV cured, in each case the methyl methacrylate can dissolve or soften an a polymethylmethacrylate part and potentially cause problems (solvent induced stress crack corrosion) in a PC part.

[Author]

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