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Top replacement on a classical
Posted: Fri Oct 15, 2010 1:00 pm
by mike789166
I have a bit of a problem with my first scratch build. When I joined the top I didn't do a very good job as I didn't have a jointing plane and used a flat surface and fine sandpaper. The joint looked ok when it was candled, but maybe the edges were rounded or something and it has a really conspicuous glue joint which will bug me forever. I glued the top on and hoped the joint would look better after sanding, it doesn't. I want to replace the top with another I have jointed using a shooting board and I am pleased with the joint as it is almost invisible. The guitar is bound with rosewood and I don't really want to have to take that off too, so I wonder if anyone has tried to rout the top off and fit the new top inside the binding and redo the purfling. I could maybe use abalone to fill the gap. Hope you can give me some of your experience. I think it would be a good learning project.
Re: Top replacement on a classical
Posted: Fri Oct 15, 2010 1:55 pm
by Ken Hundley
So many things are going to change with your new top. It will be difficult to ensure the braces perfectly fit the notches, and it will be hard to get the edge of the guitar just right to drop in again. Your best bet would be to route off the binding, separate the top, and replace it with the new one.
You might be able to steam off the binding before hand and reuse it, but my guess is it will crack.
Re: Top replacement on a classical
Posted: Fri Oct 15, 2010 6:18 pm
by Freeman
Assuming you built a spanish heel on a solera, you will have to first remove the fretboard (not all that hard) then the top. The big problem that I see is that everything is held in alighnment by the work board - you'll have nothing to keep the neck angle correct and no way to reset it after you've retopped it.
I know classicals are retopped (you might go back thru old GAL literature) but I think it would be much harder than a steel string (where you can reset the neck). It still ain't easy on a steel string.
Frankly I think it will be a huge hassle, why not learn from it and start number 2?
btw - I've had fairly good luck filling cracks with epoxy and powered wood, but I've never done it with spruce. Then all you're looking at is a refinish.
Re: Top replacement on a classical
Posted: Fri Oct 15, 2010 11:30 pm
by Ken Hundley
I didn't even think of that, good catch! Maybe the best thing is to shoot some opaque color...black, maybe tobacco brown....no damage to the guitar, and the seam will be invisible.
Re: Top replacement on a classical
Posted: Sat Oct 16, 2010 6:06 pm
by mike789166
Thanks for the replies. I know it won't be an easy task, but I like a challenge. It is a Spanish heel and fretboard and bridge have not yet been attached so that is no problem. I came upon this method for replacing the top.
http://www.grevenguitars.com/GrevenGuitars.html Look under "Extras". It looks do-able. Anyone see any difficulties or tried this method?
Re: Top replacement on a classical
Posted: Sat Oct 16, 2010 6:35 pm
by naccoachbob
If you're looking for a challenge, you got one there. I watched the slide show. Wow! Gonna really need to be precise. The purfling will give you some leeway, but be very careful, it won't be much.
Best of luck.
Take pics and post them. This will be fun and educational to watch.
Bob
Re: Top replacement on a classical
Posted: Sat Oct 16, 2010 6:43 pm
by mike789166
I will post pictures if I pluck up enough courage to do it. I was wondering why he didn't cut the purfling channel before fitting to the guitar. One advantage I do have is the use of the mold to hold the sides in position and stop any splaying. I may also use a smaller router bit than 1/4 initially and work my way out to the rosewood binding. I find rosewood is easy to hide any little dings using epoxy and sawdust. Wish me luck!
Re: Top replacement on a classical
Posted: Sat Oct 16, 2010 7:29 pm
by naccoachbob
Mike, I think he did that so that you could see where the imperfections between the binding and the top were. That way you could better judge the width of the purfling needed. Sound right? Plus, you wouldn't have to match both sides of the purfling, your cut for the purfling would "true" both the binding and top edges.
Hope I said this right. I know what I mean, but may not convey it well.
And, again, good luck. :)
Re: Top replacement on a classical
Posted: Sat Oct 16, 2010 7:52 pm
by mike789166
I know what you mean about truing both sides,but I would have to use a router bit the exact size of the purfling to cut the channel. If I cut the channel before I attached the top I could use my SM router bit to cut the correct size. I used plastic purfling strips so i should be able to scrape the residue off the rosewood and leave a clean regular surface and then sort out the purfling later. Time will tell. Anyway, thanks for the interest Bob. I am off to bed now as it is nearly 2am here.
Re: Top replacement on a classical
Posted: Sat Oct 23, 2010 1:35 pm
by mike789166
Well I made a start today. Here is the guitar

I stuck the new top on with double sided tape and then used my SM router bit to cut to size so that it just fits inside the binding.
I also cut a pufling channel
Starting to remove old top
Top off ready to cleanup
New top sits inside the binding nicely
rescued the rosette
Need to replace a couple of tentelones
More later. I am quite pleased with my progress so far.