Mahogony Restoration

[Tjriley]

I have a 1958 mfg cambridge that I just recently purchased. bow and deck are in rough shape. I believe its a mahogony veneer. See attached photo. What are your recommendations for restoring the veneer. Classic Color Stain? Varnish? Sandpaper? How many coats of varnish, etc. Also, what product is the best to clean an
unpainted fiberglass hull?
Thanks for all of the advice

 

[VolvoBoater]

Decks are usually made of teak as it can outlast most other woods. Mahogany, for example, is prized for its color and tight grain and used to be frequently used for cabins. Unfortunately, it needs to be carefully maintained and should be covered to survive outside the cabin. I'm guessing you've got teak decking, so the options are really up to your preference and climate. Traditionalists either oil or varnish the deck, but I've seen a few decks done with in polyurethane that looked great and lasted well. My favorite is varnish because it is a time tested solution, lasts, is relatively inexpensive, and doesn't require special skills to prep the surface or apply the finish. "Don Casey's Illustrated Sailboat Maintenance Manual" provides a good overview of the process of maintaining wood decks, rails, hatches, etc.

 

[Tjriley]

Thanks. Can you recommend a brand of polyurethane and color? looking for the darker brown/red color that you see on a lot of classic boats.

 

[zool]

Hey Tj, is this what you have?...may very well be a vaneer..

http://www.fiberglassics.com/library/File:Mfgb58008.jpg

post a few pics of what you have, and wood condition, a spar polyU is what you will need, but the prep and method is key, depending on condition.

Epiphanes isa a top brand choice, helmsman is a more budget friendly option....some do the lower coats in helmsman, and the top coats in the Epiphanes...you will be looking at 6-10 coats, with sanding between.

Welcome to drydock

 

[Watermann]

I refurbished a teak swim platform by first cleaning the teak with hull cleaner to get rid of the gray and once dry used multiple coats of teak oil only to seal it up. You could also use the same hull cleaner to clean the fiberglass.

 

[Ned L]

A late 50's runabout will not have a teak fordeck (unless it is something REALLY unusual). If it is any sort of a 'plywood' type material it will be a mahogany surfaced plywood. Can you post a couple of pictures so we can get an idea of the condition? Sanding should be done carefully so you don't sand through the top mahogany veneer. Depending on the condition (staining) it may benefit from some careful bleaching to even out the color before staining, and then varnish. An 'oil finish' would not be recommended for a plywood deck.
Me, .. I use a regular 'spar varnish' or 'tongue oil varnish' (exterior so that it has UV protection). I stay away from Polyurethane varnishes. They are tougher and hold up longer, but when there is a problem (water gets under) they peel up like Saran Wrap. 3 - 4 coats of varnish with sanding between coats will get you going.

That MFG literature that Zool posted, ......... Mahogany plywood deck.

 

[Tjriley]

Photos as requested. Fortunately hull is entirely fiber glass and in good shape. Just needs to be cleaned with------? The transom wood is ornamental, screwed to fiberglass. The big issue is the bow. There are a lot of cracks, couple of gouges and one section where wood needs to be glued down with____? Plastic window is in good shape. Just needs to be cleaned with----? Would like to get the red/brown color of garwoods I saw at lake Tahoe(dreamer). Can't wait to get going on this father/son project. Waiting on tune up kit for big twin Evinrude 35. Thanks again for all the help. See pictures that follow

 

[Tjriley]

no. 1

 

[Tjriley]

no. 2

 

[Tjriley]

no. 3

 

[Tjriley]

no. 4

 

[Tjriley]

no. 5

 

[zool]

hmm, those gouges in pic 4, starboard side look pretty deep, you may need to fill and fair them, then apply fresh vaneer, that's a big job, and best done removing the boards and either replacing it with new ply, or re-vaneer after a lot of prep.

really nice boat and worth the extra effort to do it right, imo.

PS, Neds right about varnish instead of PU, but with a properly applied 2 pack LPU, you will get a glossier, more water resistant, harder surface, think awlgrip. LPU is also more difficult to repair, where varnish can be sanded and repaired easier. The varnish also requires a long wait period between coats, like 24 hrs. Either one works good if properly applied.

actually, nowdays, the term urethane is treated as a noun, and varnish as a verb...you will see terms like polyurethane varnish, and alkyd varnish, ect.

 

[Ned L]

I pretty much agree with Zool on the deck. What is there may be able to be saved, but (if the wood is sound) it would take a good bit of careful work. I would start by gluing back down the spots of lifted surface veneer of plywood (careful selection of glue used and the process used so as not to mess up the ability of the wood to take the color stain you desire, followed by a careful complete stripping to bare wood. Then depending on how stained and discolored the surface of the wood is it may require a bleaching to even out the color, followed by a stain color of your choice, then varnish.
Or you could replace the deck with a good quality of mahogany plywood (such as Okume), and start fresh.

Nice boat, worth a bit of time to do the job nicely.

 

[Tjriley]

Thanks again for all of the advice. For the plywood deck, should i hand sand or use an electric sander? And what grain sandpaper? Also, what type of glue do I use to glue down loose plywood on the deck. Need advice on next step after sanding is done

 

[Watermann]

Titebond III would be good glue, just don't use any expanding poly glue like gorrilla. I would start off with some 220g sand paper with a finish palm sander, just keep it moving while taking off the old finish. Don't use one of the orbitals with the round disk, they can be tough to control and eat too much material. I refinished some bow deck supports on my Chief, while not veneer it was solid mahogany and without any stain it brought out the red color and looked great with just a few coats of Helmsman spar varnish.

 

[Ned L]

I would take a bit of a different path (choice is yours). I would start with gluing down the raised veneer first. Titebond is seems like it should be ok (never used it myself). I would use a glue that can be thinned a bit so that it can flow easily between the plies. I would also want to use as little as possible so that it does not saturate the top ply, or squeeze out up to the surface. If the top surface becomes saturated it could affect how that area accepts the color stain that is used before varnishing.
For stripping the existing varnish I would probably start with a liquid paint & varnish remover. A concern I would have with sanding off the existing varnish is that the varnish may be a harder than the mahogany veneer which can leave you with an uneven surface as the mahogany sands away quickly in bare spots. Once the varnish is removed I would hand sand using a sanding block, starting probably with 120 grit lightly to even the surface, then 150 grit and finishing with 220; always sanding only in the direction of the grain of the wood (fore & aft). After the sanding dust is well removed with a vacuum & compressed air (if you have it) stain the wood with a filler stain of choice. When well dried, finish with varnish using a light sanding between coats.

 

[Tjriley]

Thanks again Ned and Zool. Great advice. We glued loose plywood. Any recommendation for a wood filler for the gouges in the mahogany plywood and the gap where the plywood is separated? trying to save the original deck. Sanded the rubber rub rail. Can't wait to get back on the Potomac.

Best