Lacquer question

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woodsworth

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I have a customer who wants a pine worktop. I've tried to talk them out of it but that is what they want. I've been advised by my wood chap that the best way to protect it is to use nitrocellulose lacquer. Before i do this i'd like to know if anyone has done this? The wood chap explained that if any water gets in it will get a blue mould so it has to be completely waterproof.

What are others thoughts on this, recommendations for finishes, and source for buying online.

Thanks
 
I have been doing the same thing yesterday

I have been advised to use 2 pack acid cure lacquer, i have used morrels and i looks very good today

I have never had to use it on a pine top before so i dont know how it will wear, i think it will be fine from a water resistance point of view, but with the pine being soft if the top gets dented and the film damaged then the problems may start.
Tell the customer the risks and use a/c lacquer for a very hard finish or otherwise use tung oil and lots of work maintaining the finish
 
You are going to get dents...that's for sure. I would use a waterproof protection that is also flexible and moves with the dents...

You don't want something hard that will crack and let moisture in...that would look dreadful.

Jim
 
Coat it before the AC lacquer with epoxy resin, this will soak in a bit and harden the timber. The epoxy is also completely watertight AC isn't.

Simon
 
Oryxdesign":2m8fjn37 said:
Coat it before the AC lacquer with epoxy resin, this will soak in a bit and harden the timber. The epoxy is also completely watertight AC isn't.

Simon

AH! I thought you would chip in Simon...always better to get the advice from an expert!

You going to Sittingbourne on 26th mate?

Jim
 
I'm hoping to Jim. If anyone wants to pop in for a quick demo on Wests Epoxy or AC lacquer give me a shout.
 
I doubt this method is much used in furniture work, but actually an excellent method of sealing AND putting a hard skin with a lot of ding resistance over softer woods is to laminate a layer of 0.5 - 1.0 oz/yard woven fiberglass matting.

Before anybody panics this is not the hairy stuff most are used to, it's a very lightweight fabric that's a bit lighter than say a linen handkerchief and with an open enough weave to conform to 3D curves.

It's even possible as a variant to vacuum bag it while it cures to enable the use of quite heavy cloths over less sharply curved surfaces - provided your bag does not adhere to your resin/clear coat.

I've used it a lot in model aircraft construction. In that case it's common to put it down over wood by brushing a coat of epoxy resin thinned 50/50 with methanol (isopropyl alcohol would probably do the job too) over the top. A bog standard quite wide paintbrush works just fine, as the thinned resin is water like and takes no brush marks. The alcohol flashes off a few minutes after going down to leave a thin application of full strength resin which has also impregnated the wood.

It literally goes down as quickly as you can brush it on, conforms to very tight 3D curves with no tendency to spring up and the odd overlap etc is not a problem as the cloth is so thin. You could (and possibly should consider if you need an especially tough surface) using a slightly heavier cloth than 0.5 oz/yd2 on furniture work (weight is not an issue), but some experiment would be needed to select a cloth with the required ability to conform.

The surface left after the first coating is sealed, but clearly shows the weave of the cloth, and the odd almost gloss patch (depending on the absorbency of the wood - a second is normally required (reduce the resin dilution to give a thicker coating) to fill it completely. Trim off any overhang using a 180 grit sanding block or similar rubbed along the edge of the wetted area, and brush down any dry cloth left along the edge. (the cloth as a result does not have to be cut to size accurately) - this method is really quick on a corner. Then give it a quick rub with 180 paper to skin off any specks and loose glass strands. (only) Don't try to sand down into the cloth.

Epoxy works well, and if flatted with 180 wet and dry after the second coat leaves (without any primer) a really sound base for a sprayed finish using two pack polyurethane acrylics. My experience is with car paints, but i'd imagine that the furniture variety would work well too.

I've heard of this being done using other resins and paint types too (e.g. two pack clear, cellulose lacquers etc), but haven't used them

MOST DEFINITELY DON"T TRY THIS ON YOUR LATEST PRIDE AND JOY without trialling your choice of materials and methodology on the same wood and shapes, and figuring what it can and can not do. It should be OK with wood movement, but it needs some investigation and/or testing. Ditto without checking the H&S on whatever materials you use and proceeding accordingly.

That said a brushed down layer of glass cloth (using whatever clear finish you have chosen - having proven its suitability and compatibility), followed by a light rub down (you will cut through the cloth of you are heavy handed - as above the task is just to remove stray glass fibres and specks sitting on the surface of the cloth), followed by a couple of sprayed coats of the same clear finish would i expect deliver a fabulous 'mile deep' clear coating off the gun.

The extra labour would not be much given the speed with which the glass cloth goes down, the ease with which it finishes, and the fact that couple of clear coats should give an excellent finish out of the gun.

Rustins Plastic coating may well be an option for this, but urea formaldehyde while waterproof apparently does not do well if left immersed.

Has anybody else encountered this sort of method?
 
Yes, if you look on the Wests website there are some beautiful pictures of boats finished as you describe. It helps if the epoxy is warm as this makes it naturally thinner, it then flows to a virtually gloss finish especially if applied by roller.
You can get an amazing deep finish like this but it seems a little ott for a worktop!

Simon
 
Thanks for the replies, I am just researching each. The Ruskin's is looking pretty good. But i'll let you know what i choose.
 
Just to emphasise something Simon. I took a look at some boat and kayak articles (thanks for the steer), and saw talk of using 6oz woven glass cloth, and squeegeeing on the resin using plastic cards etc.

That's a very thick layer of material which will cause big problems on corners, edges and sharp radii, and a hugely labour intensive means of applying it. The 'secret' such as it is in the use of a very lightweight glass cloth, and the highly thinned very low viscosity (water like) resin or low viscosity clear coat to put it down.

This sort of thing happened all the time in modelling. People couldn't handle the idea of the watery diluted resin, and would come unstuck working with thicker 'improved' mixes. Resulting in huge time wasting, poor finishes and massive weight gain. (critical in that case) Whereupon they would assume that those getting good results must have been spending hours and hours on rubbing down, and decide the technique was too much trouble...
 
Yeah they use 6oz for strength. I'd be surprised if you would need to dilute West, when its up to temperature it is very thin. I might try next time though.
 
Have fun. One thing to be careful with O is that you need enough 'stickiness' in your resin to hold the glass cloth down. The 50/50 alcohol cut resin works beautifully on cloth around 0.6 - 1.0 OZ/yd2, but might not hold down a significantly heavier variety. It'd need a bit of testing.

A heavier weight cloth could take quite a lot of coating to fill the weave after it's initially laid down too - whereas a sprayed coat or two of clear coat after the 0.5oz is laid down and lightly rubbed back will give a high gloss finish.

The openness of the weave is also important. There is very tightly woven cloth that gives a much higher resin/glass ratio (for more strength), but unless you are on a flat surface it's not that practical without vacuum bagging. You're probably familiar, but the term used is 'drape'. I can't remember the name of the specific weave that gives lots of drape though.

I honestly can't over emphasise the benefit in terms of ease of work of using the 50/50 mix with the light cloth though - if it looked like that might be enough to skin what you have in mind it's well worth a try...
 
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