# When to use Sanding Sealer?



## Yetty (1 Feb 2007)

Are there any general 'rules of thumb' for when to use/not use Sanding Sealer? 

(The application I have in mind is a soild ash bookcase with ash veneered mdf panels, to be finished using Danish oil.) 

Many thanks,


----------



## Philly (1 Feb 2007)

Hi Yetty
Welcome to the forum!
I wouldn't use sanding sealer with oil, I'd just start applying the oil!
Hope this helps
Philly


----------



## woodbloke (1 Feb 2007)

Yetty, welcome to the forum....same here, just start to apply oil, don't bother with sanding sealer - Rob


----------



## Newbie_Neil (1 Feb 2007)

Hi Yetty

Welcome to the forum.

Cheers
Neil


----------



## DaveL (1 Feb 2007)

Hi Yetty 

Welcome to the forum.  

Finishing oil is my favorite finish, just opened a new 5 litre can. :shock: I have never bought any sanding sealer. [-(


----------



## Yetty (2 Feb 2007)

Thanks so much for the welcome and comments, genuinely appreciated. 

Seems that skipping the sanding sealer and just oiling the Ash should be fine.

Any ideas on which common types of wood / finishes where sanding sealer is useful?


----------



## Philly (2 Feb 2007)

It's not so much the woods but which finish you're applying over it. For example, if you are using a lacquer then you could use a compatible sealer as a first coat.
You don't have to use a sealer - the first coat of finish you apply will act as a sealer. Proprietory sanding sealers have additives that make them easier to sand which can make the finish more sensitive to knocks. So you can just apply an extra coat of your chisen finish instead to act as a "sealer".
Hope this makes sense
Philly


----------



## RogerS (12 Feb 2007)

Hi Yetty..welcome to the forum. A good question and after reading the replies I was wondering......

Ash is a beautiful pale wood. Does finishing oil darken the wood more than, say, sanding sealer?

Can sanding sealer be used just by itself and if so, any caveats....it seems to be clearer than finishing oil.

Roger


----------



## Nigel (14 Feb 2007)

Can I add my recent experience with sanding sealer 

I have just finished 2 Bigfoot trucks for my grand kids and applied a shellac sanding sealer intending to finish with Chestnut spray lacquer
but on talking to Terry at the recent show to be able to apply lacquer
I should have used cellulose sanding sealer and 
Wax finish is the best thing to apply over shellac type,

This is not a problem as the finish is very shiny but as Roger inquired are there any pitfalls to leaving as is 

Nigel


----------



## Terry Smart (15 Feb 2007)

Hi Nigel

Generally speaking, the top coat used over a sanding sealer (a laquer or polish usually) will be harder wearing than the sanding sealer and give better protection.
You can leave it at the sealer stage without any real problems, especially in the case you're describing, although on, say, a table top I wouldn't recommend it.


----------



## Nigel (15 Feb 2007)

Thanks for that Terry
I'll leave them as they are and monitor the testing progress from the under fives 
Nigel


----------



## johnnyb (17 Feb 2007)

i prefer very matt water based lacquer to have the least affect on the wood. solvent types tend to richen the colour, oils even more so. water based leaves it light.


----------



## Yetty (7 Mar 2007)

Thanks everyone for the interesting comments and the welcome messages.

I never even supposed there were differing types of sanding sealer i.e. cellulose and shellac based! Interesting comments from Phily about sanding sealer making the wood easier to sand which can make the finish more sensitive to knocks.

Exactly when and where to use sanding sealer is still a little foggy. As with many things, there are many products and methods to achieve a similar end result. I suspect sanding sealer is one of those variables and ingredients!

For the ash bookcase, the goal was to seal the wood, enrich the beauty of the grain, provide a finish with a soft lustre giving a more natural appearance. 

In the end, I didn’t use sanding sealer. I felt it just added another unknown. After lots of reading I achieved the desired finish with Liberons Superior Danish Oil. The steps used were:

1)	scape and progressively sand to 220g paper,
2)	1st coat of oil applied using a folded cloth, leave 24hrs, 
3)	gentle sand using 320g paper,
4)	2nd coat of oil, leave 24hrs,
5)	gentle ‘scape’ using a new knife blade (Stanley type)
6)	beeswax polish

This worked really well and achieved the desired result. Thanks again for a great forum.


----------



## Smudger (7 Mar 2007)

I'm starting from a position of complete ignorance, here, but I recently made a kitchen wall cupboard out of softwood and used a coloured water-based varnish on it. It is in the kitchen in my French holiday home, and wax and oil finishes don't do well with the changes in temperature and humidity as we aren't there all the time. It was horrible. It ran, didn't stain evenly and was a great disappointment.
I was advised to try a sanding sealer, so I ran a couple of test pieces and the varnish looks 1000% better. Much more even, no runs.
I also tried a wood dye over the sealer and got a much more controlled effect than over bare wood.

Now, given that I am not even on the first rung compared to you lot, I expect to be shown the error of my ways, but for a bodger like me, it makes sense.


----------



## Yetty (7 Mar 2007)

Hi Smudger, that’s really interesting. Some years ago I too experienced similar disappointing effects with new pine skirting board. It seems to me that you have solved one of the mysteries [to me anyway!] of where an application of sanding sealer really works to good effect. 

I wonder, when the streaky effects first occurred, was the pine fairly new? Also speaking from a position of ignorance, if new pine, then perhaps the green wood was still releasing moisture and so finds difficulty absorbing the coloured varnish. Hence the effect of streaks because the varnish sits on the surface rather than absorbing. Sounds plausible, but does not explain how the sanding sealing may miraculously resolve the situation. Anyone understand the science of what’s really going on here?


----------



## Terry Smart (8 Mar 2007)

Certain woods, pine being a prime example, don't always take a stain consistently over their area. This is because some parts are more absorbent than others.
A favourite trick to get around this is to use a thinned-down sanding sealer (usually thinned 50-50 with the appropriate thinner) first; this 'half-seals' the more absorbent areas whilst having little effect on the less absorbent areas, by virtue of how much sealer soaks in. Thus, when you stain on top of this, the effect is more uniform as the absorbency is more uniform.

I hope this makes some sense!


----------



## wrightclan (8 Mar 2007)

Terry Smart":51ujffqe said:


> Certain woods, pine being a prime example, don't always take a stain consistently over their area. This is because some parts are more absorbent than others.
> A favourite trick to get around this is to use a thinned-down sanding sealer (usually thinned 50-50 with the appropriate thinner) first; this 'half-seals' the more absorbent areas whilst having little effect on the less absorbent areas, by virtue of how much sealer soaks in. Thus, when you stain on top of this, the effect is more uniform as the absorbency is more uniform.
> 
> I hope this makes some sense!



I always use sanding sealer on softwood before staining. Occasionally, I also do it on hardwoods.

Brad


----------

