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[Phil]

Isn't there a process whereby preservative is forced into the wood under pressure so that it penetrates more deeply into the wood? It isn't my area of expertise, but I do seem to recall hearing about that treatment.

Ron.

Tanalised timber, lots of fence panel suppliers claim their products have been pressure treated.....whether they have or not...

Tanalith C is the preservative and contains (or least it used to) arsenic and generally has a greenish hue, Tanalised isn't the treatment its the stuff they use

Depth of impregnation depends on, amongst other things, the process - single or double vacuum treated - most joinery grade timber, if needed treating, is vac vac treated, same sort of stuff but dries to a very light brown hue, expensive 3 day process if done to the letter (in, treat, correct dry times), however I used to drop stuff off at the old treatment plant in Barking before 8am on the way into London and pick it up before 4pm on the way home, still dripping wet in some cases.

Closer the grain of the timber the less the impregnation.

As most 'cheap' timber is generally a fast grown (south facing) redwood the treatment impregnates quite easily and quickly, when you get to North face 5ths and sawn falling it has to be vac vac treated to be effective

[kev2b4]

i use 50/50 genuine creosote and old engine oil (preferably diesel as i like the colour)

[Terbs]

We have a timber yard 3 miles away. My friend worked there, and he used to fork lift a pallet of timber into this unit (imagine a petrol tanker body) then seal the end doors and set it working. Evidently it was supposed to force the treatment into the timber. They leave it in for quite a while.
That's all I know about it.

[Phil]

We have a timber yard 3 miles away. My friend worked there, and he used to fork lift a pallet of timber into this unit (imagine a petrol tanker body) then seal the end doors and set it working. Evidently it was supposed to force the treatment into the timber. They leave it in for quite a while.
That's all I know about it.

That's the vacuum treatment, either single or double vacuum

[baggers]

i use 50/50 genuine creosote and old engine oil (preferably diesel as i like the colour)

    

Same here, beats all the other stuff out there.

[baggers]

If you buy treated timber, how far into the wood does the treatment penetrate.
I have bought Wickes  fence posts, gravel boards, arris rails and featheredge boards. They have to be cut down, so have exposed edges. Will the weather get in where timber has been cut. In the case of the posts, is it best to put cut end in the ground or the non cut end. Same with feather edge, cut end against the gravel board, or the other way up.
TIA 

Concrete post's only way to go.

And they are not as good as they used to be, maybe made in china   
You find a lot of the old concrete post are still standing but the new stuff is always breaking up.

More expensive but better off with the galvanised post sections.

[minifreek]

They don't use arsenic in the tanalising process anymore due to too many animals/people dying of poisoning LOL

The vacuum tank is called an autoclave unit, and its the only way to penetrate softwood....

If you can afford them, get hardwood posts. They wont need any preservative for many years....


In answer to your first question, yes you will need to use some sort of sealent/preservative on the cut ends, but Id also use post toppers too, to help the rain to runoff....

[Phil]

.......The vacuum tank is called an autoclave unit...

.....If you can afford them, get hardwood posts...

Isn't an autoclave unit only when there is a heat differential requirement for curing or steam injection, so as the preservative isn't heated technically its not an autoclave, the wood leaves the treatment tank dripping wet, so its just a vacuum pressure vessel

And no you don't want to restrict yourself to hardwood, Douglas Fir is commonly used in fencing as its very strong and a softwood, Balsa is a hard wood, obvious which one you want.

Western red cedar is a softwood but contains a natural fungicide and that's why it can be used externally with no treatment at all for many many years - cedar shingles on roof being one main use

What you actually want on a cost/ availability basis is a close grain slow grown redwood which has been pressure treated.


If you can afford fence posts made out of hardwood like Iroko (which is commonly used in window and door cills), you will be loaded enough to have a metal fence 

[tigers_gonads]

Cut the timber to length and then stand the fresh cuts in a bucket of dirty 10/40 semi synth thinned out with a little white spirit or turpentine 

[EMD]

The Barrettine Wood Protective Treatment i recommended is just like the old creosote , it even smells like it . You can visibly see the stuff soaking into the wood . I use to use old engine oil but the cats kept slipping off the fence 

[tigers_gonads]

The Barrettine Wood Protective Treatment i recommended is just like the old creosote , it even smells like it . You can visibly see the stuff soaking into the wood . I use to use old engine oil but the cats kept slipping off the fence 

The idea is to coat the fence in said mixture 
NOT THE CAT