Sandblasting Thuja Deadwood

[amkhalid]

Sandblasting seems popular in some bonsai circles. I've always wanted to try sandblasting Thuja occidentalis deadwood since there are so many intricate details covered in stubborn dead bark that is very difficult to remove by hand. It can be done, but it is practically impossible to preserve the tiny, 0.5 mm diameter jins that are so charming.

I tried it with this guy yesterday. Sandblasting was done using a standard glass bead abrasive at 70 psi. The live vein was covered in plasticine and the pot/foliage wrapped in aluminum foil and shrink wrap (cloth would work fine too). Keep in mind sandblasting is really only for deadwood species with a defined live vein that has been cleaned of bark.

I am really quite impressed with the results. I never would have been able to preserve some of these details if cleaned by hand. It seems counter intuitive, but sandblasting is actually quite gentle. Sure the silver patina of the wood was lost, but that takes two years to come back in my yard and I use lime sulfur on my cedars anyway.

Before

After. Notice the bark has been completely stripped from the tiny jins.

 

[october]

Very nice end result. It seems like a lot of work as far as protecting the tree. However, the results, might be worth the extra effort.

Oddly enough, I was at the nursery a couple of days ago. They had a thuja that with the exception of having a straight trunk, it looked extremely similar to yours. Foliage in the same place, long top jin etc.

Rob

 

[amkhalid]

Very nice end result. It seems like a lot of work as far as protecting the tree. However, the results, might be worth the extra effort.

Oddly enough, I was at the nursery a couple of days ago. They had a thuja that with the exception of having a straight trunk, it looked extremely similar to yours. Foliage in the same place, long top jin etc.

Rob

Thanks Rob. Actually it only took about 45 minutes to prep the tree - its pretty small. The sandblasting itself only look like 10 minutes.

Some of my larger trees might take 3+ hours to prepare. But still, I think it is worth the effort considering the results are difficult to duplicate.

I'm not going to start sandblasting everything. Some of my deadwood trees have more coarse features which are reasonably easy to clean by hand. I will save sandblasting for trees with really fine intricate stuff.

 

[Poink88]

Nice!

I've seen some crazy good results via sandblasting and I won't mind trying it myself. Maybe in the future...

 

[mcpesq817]

Nice job - that worked out very nicely!

 

[fore]

Very cool, thanks for sharing this technique. May I ask what sandblaster/setup was used? I'd love to learn a bit more about this.

 

[amkhalid]

Very cool, thanks for sharing this technique. May I ask what sandblaster/setup was used? I'd love to learn a bit more about this.

Thanks fore, I'm glad you found it useful.

Just a standard sandblasting cabinet was used with a shopvac hooked up. The kind used for cleaning engine parts or whatever. It was small but I'm already brainstorming options like a makeshift plywood sandblasting room that can be easily set up/torn down for large trees. Important thing is that you can create negative pressure, or I think the room/cabinet/whatever will fill with dust and cloud your vision.

 

[edprocoat]

Amkhalid, looks great and I have thought about this but never tried it or even heard of it being used until now. Thanks for sharing.

I sandblast a lot in my work, I want to warn you and others out there who may try this that sandblasting is very dangerous. You should wear a proper respirator, not a dust mask ! The fines in the sand blast medium if inhaled will fill the bronchi passages in your lungs leading to many diseases such as COPD, Chronic Bronchitis, Silicosis, Emphysema and so on ...

Its far safer to sandblast outside with an approved small particle respirator, outside allows most the fines to blow away harmlessly. This is a good one for sandblasting and all you need to buy with it is the 2 filter cartridges, all told about $60.00 a small price to pay for the ability to breath. http://www.homedepot.com/catalog/productImages/300/1b/1b47fc51-0111-4b03-b269-9acf30c1636f_300.jpg

If you are sandblasting in an enclosed space the fines, minuscule particles, hang in the air almost indefinetly. If you do sandblast in an enclosed space you need to purchase an air supplied respirator, its a filtering whole head mask with an air supply, very expensive but still worth it for your health. The reason for a whole head mask is the fines created by sandblasting in an enclosed space not only can fill your lungs, they also will fill your sinus passages in your ears and can severly damage your eyes, like getting sand in your eyes, think of a sand so fine yet still abrasive as to abrade the surface of your eyes, its so fine it gets into the surface of your eyes and into the pores of your skin.

Sorry for being so long winded in this reply, but this is very important, and potentially dangerous if not correctly attempted.

ed

 

[amkhalid]

Amkhalid, looks great and I have thought about this but never tried it or even heard of it being used until now. Thanks for sharing.

I sandblast a lot in my work, I want to warn you and others out there who may try this that sandblasting is very dangerous. You should wear a proper respirator, not a dust mask ! The fines in the sand blast medium if inhaled will fill the bronchi passages in your lungs leading to many diseases such as COPD, Chronic Bronchitis, Silicosis, Emphysema and so on ...

Its far safer to sandblast outside with an approved small particle respirator, outside allows most the fines to blow away harmlessly. This is a good one for sandblasting and all you need to buy with it is the 2 filter cartridges, all told about $60.00 a small price to pay for the ability to breath. http://www.homedepot.com/catalog/productImages/300/1b/1b47fc51-0111-4b03-b269-9acf30c1636f_300.jpg

If you are sandblasting in an enclosed space the fines, minuscule particles, hang in the air almost indefinetly. If you do sandblast in an enclosed space you need to purchase an air supplied respirator, its a filtering whole head mask with an air supply, very expensive but still worth it for your health. The reason for a whole head mask is the fines created by sandblasting in an enclosed space not only can fill your lungs, they also will fill your sinus passages in your ears and can severly damage your eyes, like getting sand in your eyes, think of a sand so fine yet still abrasive as to abrade the surface of your eyes, its so fine it gets into the surface of your eyes and into the pores of your skin.

Sorry for being so long winded in this reply, but this is very important, and potentially dangerous if not correctly attempted.

ed

Thanks Ed - this is certainly useful information. After talking with my friend we are actually considering just doing it in the back lot of his company's warehouse. We will 100% wear the proper personal protective equipment.

Concerning abrasive - the silica beads I used are really expensive. Do you think regular cheap sand will give the same results?

 

[edprocoat]

Thanks Ed - this is certainly useful information. After talking with my friend we are actually considering just doing it in the back lot of his company's warehouse. We will 100% wear the proper personal protective equipment.

Concerning abrasive - the silica beads I used are really expensive. Do you think regular cheap sand will give the same results?

On wood any medium will work, the cheapest blasting sand is about $4 for a 50 pound bag. I have always considered it a packaging ploy to up the cost as all sand is silica but the silica beads are more rounded although i have not seen a difference using either on wood, there are other mediums such as corn cob, black beauty etc. the latter two would leave a coloration in porous materials such as wood though.

ed

 

[Poink88]

Good post Ed. Another option for enclosed area is a high velocity dust collector with really fine filter (1 micron or finer). I used to own one during my woodturning days.

 

[edprocoat]

Good post Ed. Another option for enclosed area is a high velocity dust collector with really fine filter (1 micron or finer). I used to own one during my woodturning days.

It would have to be high volume and very fine filtered, fine silicas are considered .01 microns to 2.0 microns, while ultrafine particles are less than .01 microns. The ultrafines are the ones that are almost weightless which float and are also the most dangerous ones. Remember a healthy lung inhales 152.163 102 16 ounces of air with each breath.

ed

 

[Neli]

Thanks for this advise. Stupid me has been grinding soap stone making pots, and have not stopped coughing for a month now....now I know why. The dust is super fine...and it must have had the same effect. My lungs feel chocked...blocked...irritated...
Never again!

 

[fore]

Thanks fore, I'm glad you found it useful.

Just a standard sandblasting cabinet was used with a shopvac hooked up. The kind used for cleaning engine parts or whatever. It was small but I'm already brainstorming options like a makeshift plywood sandblasting room that can be easily set up/torn down for large trees. Important thing is that you can create negative pressure, or I think the room/cabinet/whatever will fill with dust and cloud your vision.

Very cool! Thanks amkhalid! I looked around and found 110, 40 and 20lb pressurized abrasive blaster. What size did you use?

And Thanks for the warnings Ed! I think doing it outside is a very good idea, and less costly.