Linseed oil

[Jokerman]

Can anyone who knows the answer please get back to me.

Apart from the obvious what's the difference between boiled and raw linseed oil. According to my new Guru, Alan Herd, he cuts his French polish with 1/3 linseed oil to act as a lubricant. What type should I use.

Like most woodworkers I's as poor as a church mouse and don't want to splash out on stuff I don't need. I've got a bottle of boiled oil as well as the polish so I've got stuff at hand if it'll work. I then want to Briwax on top as a final finish.

What I'm making is a small box, using lovely figured, 1/4 sawn reclaimed planed down oak, to be a treasure box. What I mean is a quite small box, dovetailed etc in which my daughter, who's just had her first baby can keep things like the bracelet they put on at the hospital. The first lock of hair from the first haircut. Little gold or silver christening gifts from friends and family, the first baby tooth that comes out. All the stuff that means a lot at the time but ends up stuck in the back of a drawer for years and then gets lost when you move house.

Any advice would be gratefully received. Thanks people.
M

 

[Chris Knight]

Mike,
Raw linseed oil is just that, it is not really suitable as a finish because it takes forever to polymerise (dry). Boiled linseed oil is not actually boiled these days but metallic salts are added so that the stuff polymerises quickly so it is used as a finish.

Raw linseed oil can be used as a lubricant in French polishing but the amount you suggest is vastly too much - you are no longer French polishing with that amount and I can only imagine the mess you would create.

If you use a lubricant during french polishing (and it's not necessary if you mix your own fresh stuff), you need only to flick a few drops on the work surface with the tips of your fingers. The more you use the more you have to remove in the end.

 

[Greenfield Bob]

Mike most of us over here(in the US) use boiled linseed oil and mineral spirits and mix it 50/50.
I can't tell you what the difference is and I will be checking back in here to see what it is.

Bob

 

[Jokerman]

Chris, I was just going off what my guru said. I thought it was a lot of oil and that's why I was checking it out. The polish I'm opting to use (cos I've got it) is bottled and comes from Axminster. Used it before, without any oil, on some good quality oak and it seemed to work well on its own. Plenty of coats with a light rubbing down with steel wool in between, then tack rag.

Thanks for getting back. Have a good day
M

 

[Chris Knight]

Mike,
You are welcome. I would just point out that French polishing is a technique - not a type or brand of product. It uses a shellac/alcohol mixture and that is presumably what you got from Axminster (some manufacturers call their product French polish which is very misleading. Many just call it polish). It is possible to apply the shellac in just about all the ways a finish can be applied - by brush rag, spray etc. Of course its quick drying property makes some of these harder and/or less appropriate to use than others. French polishing is usually used where one is looking for a very high gloss finish and demands perfect surface preparation if it is to be successful. For most purposes, applying the shellac with a rag (preferably with some wadding in the middle) and lightly sanding between coats with a fine (320 or 400 grit paper) will produce very acceptable results.

Because you can apply the shellac in "sets of coats" as in wiping on three or four quick coats before you have to leave it to dry before repeating, the term coats can be misleading. I would only normally sand after I have a good thickness of polish on a piece - at least two sets of coats.

 

[Jokerman]

When I used the "polish" the surface of the timber was as good as I could get it. I then made up a rubber and floated on a coat that did dry very quickly. I must admit I put on 3 coats before I rubbed back and tack ragged. Then repeated the process. I've never tried making up me own stuff. I don't think I'll ever use enough to warrant making a fool of myself. I must say though that the last piece I polished and waxed came out dead good and looks quality. More of a sheen than a shine but it's got depth.

Good of you to come back.
M