CA finish on larger pieces

[mark ravensdale]

Hi all
started using CA finish on my pens abt 12 months ago and everything fine, so thought I would use it to finish some larger items and that's where things started to go wrong, I just cannot seem to get an even coat on anything bigger than a pen, I can see where one application finishes and the next one starts (sort of like a boundary line) can't do the who piece in one go so have to do it in stages (hence the boundary lines)
So can anyone help???
i really like the look of CA as a finish and it seems pretty durable too but I just cannot seem to get it to work for me!

Thankyou!!!

[Carl Civitella]

You can go larger then a pen but not very large. Find an applicator that does not accelerate the curing time of the c/a, you need to keep it wet as long as possible. I use the foam type packing material used in electronic equipment packing. I cut small swatches and use it that way. Good luck; Carl

[Alan Trout]

I do a lot of CA finishes on my pieces. On larger pieces I use only thin CA and apply it with a paper towel. You must use enough CA on the towel to coat the entire surface in one quick application but not to much as it soak through the towel as it will burn the dickens out of your hand. I do many light/thin coats, say about 15 or so to buildup the finish. About every third coat I will cure the finish with a paper towel that has been barely spritzed with a aggressive accelerator. After the finish thickness is thick enough I will start sanding the surface with 400 to 600 grit paper. I work my way to 2000 grit wet or dry and then polish with with a buffing wheel. This is the Cliff Note version of the process but with practice it can be applied to a very large piece. I use this finish mostly on pieces under 8". Here is my piece "Acorn Tea" that is all CA finish. It is a little under 8"x8" even the handle is a CA finish.

Good Luck

Alan

[mark ravensdale]

Thanks guys, I really do appreciate the help, you have already helped me find one mistake I have been making, I have been trying to use the medium CA glue but it seems I should be using thin CA on larger pieces, I'll give it a go and see how it turns out,
and Alan that tea pot is awesome !!!

[Mark Hubl]

Just a question, Alan or others who do larger pieces, how bout applying with non cellulose applicator. Aren't paper towels actually an acceleratant since they are cellulose?

[Ted Calver]

Some random thoughts. I use a lot of CA to stabilize the pith and end grain in wood bowls. Painting it on with a flux brush and keeping the edge wet works for me. I wonder if using a CA glue with a longer curing speed would give you more working time i.e. thin 5cps viscosity glue cures in 5 seconds, thin 50 cps viscosity glue cures in 8 seconds. As others have said, you need to work fast and keep the edge wet so you don't get the banding. Keep plenty of de-bonder nearby and wear nitrile gloves and eye protection. I have been wanting to do a test to see if thin CA can be sprayed on with a small spritzing bottle like the accelerant bottles. If it worked, it might solve the boundary line issue.

[Dave Mueller]

In this thread http://www.sawmillcreek.org/showthre...56-CA-Finishes there is a picture of a 10" jatoba platter finished with CA. It was applied in bands and there was no problem with overlap or boundaries. I think the BLO retards curing enough so that it blends well. I have used it on many pieces, mostly small, but several large like this platter and never had any problems.

[Alan Trout]

Mark,

I have tried other application materials, foam etc. I always come back to the paper towel I find it holds more CA which I want. With the thin 5CPS CA you are not floating it on like you would with a thicker CA. With the thin you are squeezing it out of the towel to get an even coat. I have tried thick CA's as well but find that the extra working time promotes heavier ridges as the centrifugal force or the rotating piece will produce the larger ridges. I have not had any boundary line issues with my method. It really boils down to a bit of practice. Once you get the feel for the application it is quite easy.

Once you have the buildup that is needed the real key is sanding. I do not sand with the lathe spinning. I use sanding blocks and sponges and sad across any ridges by hand. Sanding by hand across the ridges will ensure a level surface and prevent you from burning through the finish. Again patience and practice are really what it takes and once you figure it out it is very easy to get excellent results.

My acorn cap pieces are not very forgiving. With all wood pieces you can get by with many different methods which I have. But acorn caps are very susceptible to humidity and expand and contract much more than wood. My CA only method is the only method that I have found that works with these pieces.

Alan

[Russell Neyman]

I did not realize that this thread existed when I posted this one:
http://www.sawmillcreek.org/showthre...Large-Projects