Problem sanding sealer

[urban-wombat]

Some time back I purchased a can of sanding sealer. ( one in the black can with a double barrel name) and it worked very well just brush it on then next day sand back .. the finish was first class.. I have since used it all up so got another can same brand.. so use it as I did before.. now the problem .. as soon as I start with the sand paper the surface becomes glass hard and only a small amount of the sealer is removed ..brush strokes can be seen on the surface.. I have used other grades and types of paper..with little luck.. the more I sand the surface it gets a polished look covered in ridges caused by the brush strokes*..any idea what is going on ..the old can looked the same and when brushed on was covered in marks .. but just a light sanding would give a flat mat finish with no marks..Col

* only a single coat at a time and not over worked

[Gumby]

I never heard of leaving it on overnight but I use Neil's

[Ashore]

Same brand used the same way? diffrent results?
Was the second can stirred/ mixed well before use
Wonder how long it was sitting on the shelf before you got it?
are they still making it from the same factory/ country?

Go to the manufactures web page & see if theres a link to a support service or a way to contact them with your complaint, mabye there was a bad batch ? :confused:

Rgds

[JupiterCreek]

I use the uBeaut sanding sealer if I just want to raise the grain and it's great, but if I want to really fill and sand I use the Feast-Watson sanding sealer... which is in a black tin with a double-barrelled name so I'm guessing this is the stuff.

The first time I used it I stirred it really thoroughly and it worked a treat. A week later I used it again.. it looked the same so I just slopped it on. It did set like epoxy almost and I had to break the surface with the belt sander to kill the brushmarks before I could use the random orbital sander. Since then I've always given it a good stir and the results have been good. The stuff is always thick and gluggy, but if you get your stirring stick right down into the corners of the tin there's some really heavy sludge there that needs to be stirred in.

[urban-wombat]

I will make sure it's given a good stirring.. and let you know how it goes..

[ubeaut]

Sanding sealer with filling capabilities like the ones you describe must always be stirred thoroughly before use to enable the silica etc to be fully incorporated into the mix otherwise they are pretty much useless and can't be sanded back.

EG: Shellac will sand back reasonably easily, but will clog sand paper however add a little talc to the mix and stir it through thoroughly and it will sand back much easier and to a silky finish and with little or no clogging of the abrasive paper.

Let it sit for a week or so and it will look the same but won't work the same until throughly remixed with the talc.

Cheers - Neil

[echnidna]

How much talc should you put in the shellac Neil?

[ubeaut]

No more than a teaspoon of talc to 100ml of shellac. Works best with orange and coloured shellac but will work with all others as well.

Don't use talc from the shops, most has other stuff in it including fragrance oil that could cause problems, and some even has fillers that can leave white specks in the grain. You need to use pure talc Click Here for a bit more info on using talc. There is no info in link for using talc in shellac.

Cheers - Neil

PS the talc in the above link is 100% pure and many more times finer than off the shelf talc.

[urban-wombat]

up-date on the problem... gave the can a really good mix.. but no better than before..guess is one for the bin.. Col

[Pops]

Hello all,

Thanks for starting this thread Col and for all the helpful advise provided by others, particularly Neil for those little gems. I guess I should buy that Finishing book, (written by Neil ??).

This has been, as usual most informative, thanks fellas.

Cheers
Pops

[urban-wombat]

Hello all,

Thanks for starting this thread Col and for all the helpful advise provided by others, particularly Neil for those little gems. I guess I should buy that Finishing book, (written by Neil ??).

This has been, as usual most informative, thanks fellas.

Cheers
Pops

I'm thinking I should get the book as well

[ubeaut]

Forgot to mention this, thought you might get a bit of a laugh from it. This is the shortened version of the story.

Our talc also caused a toxic substance scare at a certain overseas Postal Centre (shortly after 9/11) when white powder puffed into the air after a box containing 2 kg of the stuff was dropped from a great height during typical careful postal services handling.

We received a 3am phone call from some official sounding twerp demanding to know what was in the package, even though it quite clearly said Pure Talcum Powder on the declaration form stuck to the outside of the package.

Turns out they had a full team of hazardous substances people in big puffy hazmed suits and had evacuated the centre and half a city block etc etc

After getting over my initial shock and amazement and finally waking up properly I said "Didn't you read the declaration on the box that said Talcum Powder."

Reply "No it was underneath the box when it fell."

(Found out later that half the writing on declaration was scrubbed off and illegible because the postal idiots had been kicking it around the room playing soccer with it, apparently this was when the puff of powder came out and they ##### themselves. But that and the cleanup demand on us is another entire story.)

They could however read the address to where it was going and where it was sent from as this was on the side they could see. They promptly sent a bunch of storm troopers around to the doctor to whom it was addressed and burst into his night-time surgery demanding answers and scaring the ##### out of waiting patients.

Like I said this is the shortened version, the full version is much more laughable. The whole incident has often given us a good laugh though.

Also gives post office staff at this end a laugh every time we mail it out now as we have signs like NOT DANGEROUS - NOT DRUGS - NOT TOXIC - JUST TALC plastered all over the outside of the carton.

[echnidna]

Truth is stranger than fiction

[ubeaut]

Urban and others - Talc is Magnesium Silicate Hydroxide. Yes it is also known as French chalk but this can be a bit confusing, as Chalk, also known as whiting, is actually calcium carbonate and there is a big difference.

You can use talc in a mix as sanding sealer as it is translucent and as a rule won't leave white in the grain unless you use way,way, too much or use the regular stuff from the shops which may actually contain some chalk.

Chalk on the other hand will act like a paint and will blanket out the grain of the timber.

Cheers - Neil

[Hickory]

Urban and others - Talc is Magnesium Silicate Hydroxide. Yes it is also known as French chalk but this can be a bit confusing, as Chalk, also known as whiting, is actually calcium carbonate and there is a big difference.

You can use talc in a mix as sanding sealer as it is translucent and as a rule won't leave white in the grain unless you use way,way, too much or use the regular stuff from the shops which may actually contain some chalk.

Chalk on the other hand will act like a paint and will blanket out the grain of the timber.

Cheers - Neil

Why does a Wood Chuck have to become a Chemist to get a decent finish?:mad:

*Used to be all you had to worry with was what thinner cleaned up the mess. Oh well so goes progress.... \

Back at the original post. and why this can of sealer took too much effort to sand down the marks than the previous can. Stirred not shaken is a key comment (Wasn't James Bond who invented that phrase?) Or does one consider the weather. And the drying conditions? Arid or humid conditions create a difference in the hardness of the finish (sealer) and the results are different. Also if you didn't change paper from the last can you will have a harder time sanding Turn it over, rough side down

Also, I have bought products and found different results (Brand name products) Some times Schmidt Happens.