With the thwart glued and stabilising the hull I was now able to proceed with stripping varnish from the inside.
Although there is still some varnish left on the timber, with canoes of this type that are not covered in fibreglass and epoxy they rely on a really good coating of varnish to help keep them from leaking so with that in mind I decided that despite the obvious amount of work involved it had to be done.
Although it is a long time since I have done any stripping of paint or varnish I did do a fair amount of it when I had my first cabinet making job so I am not without experience in this area. I was also taught how to do it when I was at college learning to be a furniture production manager where it was drummed into us that it is a last resort because of the amount of time it takes and to avoid it at all costs!
The process sounds simple enough. You apply a chemical to the surface. The chemical breaks the varnish down and you remove the varnish.
It sounds good but there are a few things to bear in mind.which I have outlined below.
1.Timing is crucial. If you try to remove the varnish before the stripper has done its work you end up lifting the stripper off and the varnish is still there or half there! If on the other hand you leave it too long and don't keep it supplied with stripper it dries out and you have wasted time and materials.
2.You have to keep the surface fed with stripper so it doesn't dry out until it is ready to lift and the timing for this can vary depending on the material you are stripping and the amount of layers.
3.Once you have lifted the gunk off the surface must be well cleaned with water or white spirit to neutralize the stripper or else when you put your new varnish on it will blister. When I was a student at High Wycombe in the 1980's our polishing Tutor Mr Turner used to become very animated and say “I beseech you gentlemen you must neutralize!” Lets just say it's important.
4.One application is rarely enough and as you will see in the following sequence of pictures the chemical is applied by stippling and stippling again and again. I put a clock in the pictures so you can get an idea of the time it takes and this is not strictly the same. Sometimes a similar area can take twice as long like for example the area under the decks which is very difficult to work on.
We begin with applying the chemical which is done with a brush over an area of about a square foot.
After this first application I wait five minutes which gives me time to clean my tools left from the bit I completed previously (on the left)
Next I stipple on another coat pushing the bristles into the surface.
Then I test it periodically removing it by lifting with my plastic scraper made from an old squeegy which I cut to fit the gap.I also have one that I cut narrower so I can work on the stems and another that has a concave cut out to fit the ribs.
eventually I begin lifting off the varnish in a systematic fashion. The trick is to apply more stripper and leave it longer if this is a struggle. You should not have to scrape too hard it is more a case of lifting the material off.
It is inevitable that you will not get every last bit off but the idea is to get as much off as you can before using a Scotchbrite pad to finish off. Scotchbrite is a plastic version of steel wool which is better because it doesn't leave particles of metal in the surface that will later rust. If you ever do any stripping on oak you will find steel wool even worse because it reacts with the tannin in the oak and leaves black marks so Scotchbrite is best.
Use it dipped in stripper first to remove any last bits of varnish
and then wash the remaining residue off twice or even three times changing the water and cleaning your tools to neutralize.
The thing is the paint stripper contains wax which rises to the surface as it works so you have to get rid of it or your new finish will not stick.
Finally dry it off with a clean rag. It is important to dry the rib at the end where you are about to continue stripping ready for the next application of stripper because if it gets diluted it won't work!
Once the surface has dried there may still be some varnish left on it but this will be removed by sanding.The point is you will not be using tons of sandpaper as the amount of varnish is not going to clog it up like it would if you hadn't stripped the surface and used sanding alone.
Now all that remains is to repeat the process again and again and again to do the rest of the hull but do not despair just look at the lovely wood that is revealed!