Hollow Form finish to the inside

[Mike Gibson]

After turning a hollow form (which cannot be easily examined inside) is it correct to use a sealer/poly/oil or whatever your preferred finish on the inside? if so do any members use a cheaper finish rather than some highly priced finish that you would use on the outside.

 

[Steve Worcester]

I try not to make the holes big enough to see inside, and not finish the inside.

 

[Ken Grunke]

From reading comments on various forums on the subject of finishing inside hollow forms, it seems most turners don't unless you can see and feel inside.
If you make the opening smaller than a finger, you don't have to worry about the inside.
So many folks rely on the sensation of touch to judge a surface so just don't allow finger insertion. 1/2" or smaller opening, maybe 5/8".

 

[Barbara Gill]

I guess I am not the norm. I always use a fairly thin penetrating oil finish. I usually pour some into the hollowform and pour out the extra. It seems to me I get a better finish on the outside if there has been finish applied to the inside.

 

[hockenbery]

In most cases the inside finish cannot match the outside finish.

The outside of my hollow forms have multiple coats of finish rubbed down between coats. I usually use the Beal buffing after the final coat.
Light wood hollow forms I often finish with spray lacquer.

I can't do these things on the inside so I don't try to finish the inside.

On forms with voids I sometimes bleach the inside to have it catch more light inviting people to look inside. I use no finish over the bleach.

If I put a finish on the inside it is often watco. It is thin enough to spread evenly and won't gum up with one coat.

happy turning,
Al

 

[Hugh]

I'm with Steve on this one - make the hole small enough and you do not have to finish the inside. But, if I color the outside of the vessel - then I do color the inside also.
Hugh

 

[robo hippy]

I also do flat work, and with it, you have to put equal amounts of finish on all surfaces, like table tops. If you don't, you will get uneven absorption with the humidity changes which can cause uneven movement, and you get more warping. I like to pour some oil on the inside of the form, slosh it around, then turn the vessel upside down for it to drain. While hollow forms are a lot thinner than the table tops I do, and warping and uneven absorption may not be a problem, it is an old habbit.
robo hippy

 

[Paul Andrews]

Regardless if the hole is large enough to fit a finger inside, I like to coat the interior with an oil finish. Not sure if it is needed but I feel better knowing that it is coated. Usually if the opening is small I just pour some BLO in and swirl it around and dump the excess. If the opening is large enough to see into I coat it with what ever I coat the outside with.

 

[Mike Gibson]

Thanks for the reply's, I am from the old school of carpentry where all sides had to be sealed and one of my concerns was as Robo Hippy says without a finish on the inside the form would be subject to uneven changes from the humidity and was wondering if any turners had a problem from not finishing the inside.