Thread: Grain/Pore fillers

Hi Mike

Good on you for ordering the shellac and talc.

I'd also suggest you aim to get a copy of the Book of Finishing also written and sold by U-Beaut as this will help you a great deal in the filling and finishing of your guitars. It will give you a confidence boost too, kinda like a holding hand while you learn and experience the finishing steps.

Cheers
Wendy

Link to above mentioned book

Mike,

Some comments on pore filling.

1. Shellac and talc. I havent used this method and I dont know of many luthiers who do.

2. Pumice and shellac method. I use this method off an on. What youre doing is using the pumice to grind up the wood fibres and create a paste which you work into the pores. The best tutorial Ive seen for this method is by the Milburn Brothers. This method does work but it requires a bit of skill and care. Major downside Ive found with this method is often ending up with too much pumice on the guitar which ends up having to be sanded back. Note the Milburn Brothers advice on only doing a small area at a time, not adding shellac to the pad and not using too much pumice. The pumice I use is Belhen's 4F grade from the US.

3. Z-poxy. This stuff is an epoxy finishing resin and its used by alot of luthiers in the US and also here in Australia. Ive used it on a few instruments and I like it. It doesnt require as much skill to apply as with the pumice method and overall its a quicker method of infilling. There are two schools of thought on applying the stuff. You can either apply a single coating of the stuff full strength making sure you get rid of any spread marks. If the first coat doesnt fully pore fill then put on a second coat of z-poxy diluted 50:50 with alcohol (I use industrial grade meths). Method 2 entails applying the z-poxy, letting it set and then sanding back to bare wood. The z poxy will remain in the pores. I usually do two coats using this method and use diluted z poxy for both coats.

4. Other methods. A variety of other fillers have been used on guitars. Egg whites were used by Torres. Robbie Obrien's DVD covers using sawdust as a filler. Robbie's DVD is well worth getting your hands on as it covers all aspects of guitar finishing. I know a few luthiers using Timbermate's filler.

Cheers Martin

I will speak for the "ready for use" Paste Wood fillers, this RFU fillers comes in several colours, they are a heavy bodied paste, they are made up in different chemials, a common paste wood filler is silica mixed with clays, but there are others

It is applied with a brush, I prefer a cloth working in a circular motion to pack the filler into the pores, some finishers use a heavy burlap to remove the excess filler off, most finishers today scape it off with a plastic scraper.

Start off by doing a 15" x15" area, and gets some practice working with the filler, do not allow the filler to get hard, because it really gets very hard and makes it difficult to remove. Watch the filler after you apply it, once the fill starts to dry, thats when you start scraping and remove all of the filler off, then move on to the next area.

Some finishers do it with 2 fills to make sure that all of the pores are filled, this reduces the amount of coats that you will need to finish your work.

Its not an easy job working on large or suites of furniture, in most casses only the tops will get filled, in your case its not a big piece to do, but it will improve your final finish.

Are you staining first? or will you be leaving the wood natural. If you stain the wood first, first apply a seal coat before you fill. If you leaving it natural you want to seal the wood before you paste wood fill.

Good Luck