Oil & Sealers

[BozInOz]

A few timbers I've used seem to act as sponges for oil. Amazing how much they absorb, others just don't seem interested.

One blackwood plank seem to suck in oil, only a month later it leaked back out. (Not a good look.) Another blackwood piece was perfect. Strange. I had a similar experience with maple yet no issue with huon.

Questions:

• I assume it's some wood is more "porous" rather than if it's soft or hard. This correct?
• Is using a sealer before other finishes a good way to stop this? eg. Feastwatson proofseal?
• Will a sealer prevent good penetration of oil?
• Will a sealer change the colours I get from oiling?

[zanclodon]

I have the exact same set of questions.

I put danish oil on an old hoop pine door a year or so ago and it drank up so much of the stuff that the timber went VERY dark and you can see the slightest sanding scratches (despite laboriously fine sanding). On the remaining doors I was wondering about using a sealer like FW Proofseal or shellac under the oil. Will the oil still harden properly? How will it look?

Maybe this time round someone has an opinion...

Cheers,

Tom

[durwood]

You are talking about two different processes for protecting timber. You can oil timber or use a system which applied uses a sealer to prevent soaking in of the top coats.

Oils applied to the timber soak in and being oils offer protection especially from moisture. dependiong on their colour they will bring out or add to the colour of the grain. You could used engine oil if you wanted but its usually a lousy colour/smells stays sticky on the surface and will always be oily, so only selected oils are used, those which go on, dry out and offer protection from water and other liquids and grime. But being a liquid they offer little in protection for the surface as they soak in and don't build up into a coating as thich as a varnish or similar product does.. If you scratch oil surfaces there is little coating over the timber to prevent the the timber from being damaged. You therefore have to be careful what you actually use the oil on. It works on furniture but not really good for a floor. its easy to revitalise as you can usually wipe on more if needed during its life after a rub or wipe to clean the surface.

Sealer is exactly that something which seals off the timber preventing the soaking in. Its purpose is to enable other finishes to be applied onto the surface and not soak in. As you have mentioned some timber takes in lots of liquid others less. Expensive coating would be wasted if the sealer wasn't there to provide a blocked off surface so they can dry on top of the sealer.

Obviously if you have sealed off the timber the oil is then only able to sit on top and will probably be of not much use as a finish you would be better off using the finish the sealer was meant to help.

[Claw Hama]

Generaly with Danish oil you only put about two coats even if you think it needs more.

[zanclodon]

Thanks for replies. Yes, I understand the difference between oiling and varnishing, and the use of sealers in the latter. However, I've heard a number of times of people applying shellac prior to oiling and have seen a few mentions of it on this forum from folks who seem know what they're on about - for instance a finishing schedule of shellac, stain, then danish oil. This seemed odd to me as well, but I wondered if it might solve my problem of excessive darkening of the pine. I did only apply two coats of oil, but after seventy odd years completely dry the door absorbed it like a sponge.

Another finish mentioned here and there is wax (like the UBeaut one) over a coat of shellac. Maybe this is what I'm after. Any thoughts on appearance, durability, suitability for internal doors?

[durwood]

People come up with all sorts of systems, often they are not practical. if you look at the normal proceedure for stain for instance its usual to apply stain as the first step to soak into the wood. it is then usually followed by a filler or sealer and then a coating of oil or other.

If you want a to avoid excessive darkening then tthe way to do it is to apply a weaker solution (you can always put on more, but its hard to go backwards.)

It always depends on what you are trying to achieve, some products may give the effect you want ( say light tone etc) but may be wrong for the object.

Eg Shellac seals and may give you the correct colour you want but if the timber is subject to heat or sunlight it will quickly breakdown.

Same goes for oil or wax they might not be the finish needed for the appication.

Often the odd seal with shellac and /oil will be OK but it depends on the traffic it will be subject to. If the doors come up as you wish then you have to keep in mind what you have on the surface, If the wife likes to clean everything with a strong household cleaaner regularly she will quickly wash away your finish or it may become grubby with the kids putting their dirty hands on it every time they pass.

How will it be on pine ? how long is a piece of string? depends on the actual piece of timber, do tests see what it takes to get what you are after. if you have a lot of timber to do it may be necessary to alter your mixes and number of coats the pine may vary a lot in colour or how it is affected by your choise of products.

Still confused- stick with the normal product specifications, lots of time and money is spent testing products before they are sold. Those proceedures work and are sold and advised to prevent disasters that can occur if you decide to make up your own system or follow someone elses. I'm not saying some of those won't work but if they were so good then the manufacturers would also advise they be followed. You may be fixing one probem and making another that is worse.

I personally can't see any advantage in shellacing/waxing a door when the same visual finish can be obtained by using a good commercial coating such as an enamel/polyurethane which will take lots of abuse. but everyone has there own ideas.