Tricky situation - advise from wise heads

Hi all, first post after jumping over from the renno forum. I'm making some timber implements for a client in the coffee scene and need some finishing advice. I need a finish that is very, very durable, food safe and can handle upto 90 degree C briefly without been damaged. The timber type varies but I mainly use spotty / ironbark / kwila or a mix of all depending on what the client requests. Ive tried rubbing tung oil with wet and dry ( 800 )and buffing after dry sanding to 240 but the shape of these things is pretty strange and hard to work. Would poly be any good ? Presentation is pretty vital and I'm after good lustre.

Cheers for any advice

For durability - epoxy, followed by two-pack polyurethane. Both are essentially a form of plastic when cured and are probably the most food safe options.

If you've ever eaten any acidic canned foods, like canned tomato, you've already eaten food that's been stored in a tin lined with epoxy!

Tung oil is not particularly food safe, as people with nut allergies may react to it.

You could also message our benevolent forum sponsor and ask how his crosslinking Hard Shellac is with 90 degree temperatures.

I'm assuming these things are for internal use; if it lives outside, continual UV exposure may cause the epoxy to degrade over time.

Cheers MS, didnt think I'd run into you over here, then again I should know better :D The item is indoors only so UV not a issue. The temp exposure would be for less than 5 seconds at a time and would be hot metal. Didnt think about the nut allergy thing which in hindsight is extremely relevant given the direct contact between the timber and the coffee.

Just guessing here but are you making a tamping station by chance?

If so <5 sec contact is normal busy use in a commercial setting but it can be many 5 sec in a day in a really busy environment. Sometimes too a delay of a minute or so will happen. Not sure if cumulative heat effect will come into play.

Brass portafilters have some heft too so expect a bit of bash and dent over time.
You've probably discovered this already.

Can you post pics or will they be commercial secrets ?

Hmmmm, maybe they are tamping stations, maybe not :D:D. Ok they are. A lot of different prototypes at the moment, 1 doing field trials in a cafe and 2 on rotation in my own " home cafe ". Totally agree with the longer than 5 seconds thing, and the heat - way too hot to touch. The tung oil rub copes easily but just doesnt cut it for bringing out the beauty of the timber. They look great for a day then dull off.

What about going to a high density timber with fine sanding? Then you would not need a finish at all.
Surface coat finishes will develop a crack or scratch which will allow water and or steam in causing the surface to lift.
Suggestions for high density timbers: Brigalow, Mulga, Gidgie, etc

Oh yeah I recognize those pics Ringtail. At least they will more more appreciated over here.

Hmmm, you have me wondering dabbler - you member of any other forum, maybe coffee related ?

Why yes! How did you know?

Seriously, I do like your work on the tamp stations. They're just not pornographic enough for most CS members although some like wooden handles. If you can maintain the lustre of the tamp station maybe they'll catch on.

I only have limited commercial experience with coffee but I reckon there's a larger accessory market at the CS consumer level than in retail coffee.
d.

Totally agree, we are a fickle bunch that confuses form with function and seem unwilling to settle on a comprimise and lean towards the bling factor no matter how bad the function

Ok, I had a dabble with epoxy ( glass coat). Great finish as long as you only want to do a horiziontal surface. Super frustating ( read impossible) to apply to a vertical surface. So, anyone got any tricks for applying expoxy to a 3D object all at once or am I better off using a flooring product like cabbots CFP ?

Apply it just like paint. Built it up as a number of coats - thin layers, applied while the previous layer is still green so they bond to each other, and a foam roller or brush to put it on with. Not sure how well this works with glass coat, but it's fine with West or Boat-Cote epoxy.

I'll give it a go MS, cheers. I'm going to have a shot at casting over easter. I'm reading a great thread on it via the search and it seems that polyester resin is the go over epoxy ? Thought it would be the other way round but there ya go.

I have no Idea if it is suitable, I suggest you give Rustins Plastic Coating a try, it is heat resistant, can be cleaned easily it is easy to work with and is very durable, I have a goblet that was fiinshed 8 years ago and is still going strong with regular use, I have also used it on coffee tamp handels

Thanks china, I'll have a google

The rustins looks perfect. I wonder if you can cast with it - cant see why not but I'll ring the store at The Gap ( bris) tomorrow. Thanks again China.

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Originally Posted by Ringtail

Hmmmm, maybe they are tamping stations, maybe not :D:D. Ok they are. A lot of different prototypes at the moment, 1 doing field trials in a cafe and 2 on rotation in my own " home cafe ". Totally agree with the longer than 5 seconds thing, and the heat - way too hot to touch. The tung oil rub copes easily but just doesnt cut it for bringing out the beauty of the timber. They look great for a day then dull off.

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if it's a tamping station do they need to be food safe?
"food" i.e. coffee grinds left in the station go into the bin, not the next cup, right?
and the base of the tamper rest could be left natural timber

Quote:

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Originally Posted by Ringtail

... polyester resin is the go over epoxy ? Thought it would be the other way round but there ya go.

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Some people confuse polyester resin with epoxy resin; but you could be thinking of polyurethane over epoxy which is (one of) the ways to protect epoxy from UV damage - but the poly is there just to keep the UV off the epoxy; it's the epoxy that's doing all the waterproofing (and by waterproofing, that's 'build it with no structural fasteners other than epoxy and sail it in the ocean for 20 years' waterproofing, not 'keep some splashes off it' waterproofing)

Quote:

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Originally Posted by ian

if it's a tamping station do they need to be food safe?
"food" i.e. coffee grinds left in the station go into the bin, not the next cup, right?
and the base of the tamper rest could be left natural timber

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True, but I have other items where there maybe contact so ideally looking for a finish that complies to some degree.