Desilva and a Yamato

[Riverrat13]

I grew up on the St. Lawrence river and have been obsessed with boats since day one. My interests were and still are heavily influenced by my father who is a wood boat addict. Our family boat growing up was a Chris craft rocket which we still have.

Raceboat weekend at the Clayton boat museum was my favorite! Always loved small fast boats! I had a 10' hydro with a big twin 25 on it for a short time (before the bottom blue out and it sank) that really got me addicted. My brother and I bought a 76 15' baja with an inline merc that was our ride in the teenage years.

Anyways, I finally have purchased my first race runabout and motor. Restoring the boat will be my winter project and the boat will be used strictly recreationally. If it turns out nice I would love to take it to some vintage race shows where I can run it.

The boat has a registration and it says it is a 13' 1960 Desilva. It's not in too bad of shape. The paint is toast and does need some wood repairs but structurally it's a good candidate for restore. It has all the hardware including a center fin that was buried way up under the deck. I'm new to wood working so it will be a learning experience. I think I'll be adding quite a bit of filler in spots and a thin layer of cloth on the bottom. But I'll be researching this whole process to figure out what's needs to be done.

As for the motor I bought, it is a Yamato 80. I purchased it off Scott reed and he was kind enough to spend about two hours going through the motor with me. At the moment it has the original prop shaft and no prop. I talked to a few people at the raceboat show this weekend and am hoping to find one. But if any one has a prop they don't use anymore please let me know. This will not be a running rig til next spring (hopefully) so I have some time to get one.

I'm looking forward to getting this project going. I appreciate any and all tips or info you guys and gals have for me.

[Tim Weber]

You have a " KR" model Desilva.
They did not make them until 1970-72?

You probably have an old pro boat or modified hull.

Desilva marks the hull ID usually on the keel or transom. It will be the class of boat, month, then year.

If you can accurately identify the code, Ralph has all the original records. His number is 770-943-9494.

Tim

[Riverrat13]

Thanks for the info! I'll check for that code. What motors did this hull race with in those classes?

[ottawamercguy]

Riverrat13 I have one of those original props and lots of the Yamato shear pins.
I will be at the Crystal Lake race, if you have not bought one by then, Look for 4-CE
in the pits.

[Riverrat13]

I should be there! Thank you so much for the response!

[Riverrat13]

So I've moved into my new shop area have started the process on the boat. My plan is to replace all the top sheet. It's the worst part of the boat.

I've started stripping the paint and removing nails. Not the easiest task haha. I will take the top sheet off by section and use them as patterns and replace.


Still haven't really found out who built the boat or what class it was.

Plan on getting 3mm okoume then epoxy and varnish.

Any and all tips are appreciated. This is my first venture in boat restoration.

[dwhitford]

It's probably easier to build a new boat from scratch than to repair and restore an old one. Just take your time and be careful.

Your 1st photo shows a traditional bronze ''ringfast'' nail, and yes, they are hard to remove, which is why they are used in the first place . . . unlikely to come out while running the boat.. They are also hard to drive straight without bending them. If you choose to use new such nails in your repair, be sure to drill tiny pilot holes for them b4 just pounding them in.

A simpler, faster way to attach plywood panels is with an air stapler. The epoxy ''glue'' secures the panels. The staples are just the ''clamps'' in lieu of the bronze nails.

I suspect that Tim Weber is correct: that you have a DeSilva KR, or if not, a good copy. Tim is an authority on DeSilva boats and good friends with Ralph, the 90+ year old surviving DeSilva brother.

Scott Reed has built probably 30 race boats and is a great source for boat-building savvy. He's a good person for you to know.

[Riverrat13]

I completely agree that it would most likely easier to build new but I thought it'd be nice to save one. And a good learning experience. The frame and bottom of the boat are very solid. It's just the top decking that was all delaminating. The nose will also need some repair.

As stated before this will be strictly a pleasure boat. Maybe take it to some wet shows.

Fran Johnson stays at my families cottages during the crystal lake races, my dad calls him "the Johnson with a Mercury". He took a look at the boat when he was up there and thinks it's a desilva copy. Could not find any ID number and some of the details didn't look right to him. It's about 12' 4" long.

Scott has been a great resource for me. I shoot him a random question ever so often. I think by now I owe him a case of blue!

[dwhitford]

If your boat was ever raced, it's about the right size for a 1970s-vintage 350 cc (''B-Class'') Koenig alky engine or a C-Modified gasoline engine. It's too small for a good 500 cc alky or a current 44 cubic-inch Merc Mod engine. You should get a nice safe ride w/ your Y80.

[Riverrat13]

Thank you so much for the info! I am going for an original wood look so that info is much appreciated.

The original nails are recessed and that's why it is really taking some time. I'm using a 3/8 ceramic hole saw around the nails. It doesn't cut too well obviously, but it does sand out around the nail so I can fit my cats paw under the heads. Unfortunately most of the heads fold then break off. It will be a long process but I have all winter. Or as long as it takes.

Does anyone know what kind of motor/hp was originally on this size boat? As stated I have a Y80 for it with a stock brass prop. I know it most likely be a speed demon but from what I've heard it will still get up and go pretty well.

[ZUL8TR]

It is good to save old classics, they are originals only once. Ex my Wetback (the one in my Avatar) I built in 69 from Kelly plans and raced in APBA Region 5 in the 70's and now use at AOMCI meets; has been repaired a few times and still structurally sound and I keep it up because it has heritage to me. I agree it is easier to build a new one if the old one is really beyond repair. But if you checked it over carefully and the bottom and side structure and their skins are in good shape than the deck replacement is easy. I see you need some repair on the side skins but looks minor.

You say you want to remove the deck in sections to get a pattern. IMO no need for that just pattern it out with heavy paper then remove the deck with less concern. Tip on deck removal: I use a small cats paw to remove nails then set the router with a flat cut bit to the depth of the plywood and buzz the plywood away over the deck stringers and cross members. If done careful just clean stringers and deck beams with a sharp low angle palm plane (very helpful tool) and then a sanding block with 180 grit to final fair for good ply fit.

I only use Okume plywood. I attach ply skins with thickened epoxy (cabisil silica thickener). I have used 316 SS (preferred) or silicon bronze anchor nails some use staples. For 3mm decks I use #15 x 3/4" nails set flush. I prep new ply with 220 and use 2 coats of epoxy (follow instructions for your brand between coats) sand dull (I use orbital sander with 120 grit) and finish clear with brush on 3 coats of exterior varnish (I get good results with Minwax spar urethane tips available). Some use auto clear coat sprayed on or a color paint.

I have done a number of restores, as have many on this site, so ask away for help.

[dwhitford]

Yeah, that Minwax spar urethane is good stuff and at about $15 a quart from WalMart, about half the price of so-called ''premium'' urethanes which are little - if any - better. Dave Curtis, a professional canoe builder, put me onto the Minwax.

[LarryR]

The Minwax spar urethane is the stuff labeled "Helmsman"?
If so, it also comes in spray cans. These work well with many thin coats.

[ZUL8TR]

Yes I have tried many varnishes like Epiphanes, Interlux, Pettit, and others and for the race boats that spend a lot of time protected from the weather and for 1/2 as much $ Minwax does an excellent job. I have also used it on furniture for outdoors and it holds up very well here in Central Fla.