Petrel

[Unregistered]

I came across a Design of a 16 Feet sloop "Petrel" on the website at http://www.svensons.com/boat/
The description and drawings specify a centerboard for builing by amateurs and alternatively a keel for the more experienced builders. I do not consider myself as very experience, but given the right tips I feel confident of carrying out the job. Hence, I would appreciate any tips or instructions about making the actual keel, type of wood or other materials to use, and best method of fixing it to the hull.
Thankyou
Rocco

[gonzo]

It is more difficult to build a trunk and centerboard than attaching a keel. The easiest keel would be a steel plate welded to a flat flange with the shape of the bottom.

[Rocco]

Thanks for your assistance Gonzo
I suppose that if I use a steel plate with flange, there is no need to be for it to be the size as that shown in the drawing. Maybe I can go for a shorter one with a ballast at the tip.
Building on your idea, if I were to remain loyal to the original design by using the wooden keel, can I build it up of say nine layers of 2 inches thick planks bolted though using half inch stainless steel bolts. I welcome any suggestion.
Thanks again
Rocco

It is more difficult to build a trunk and centerboard than attaching a keel. The easiest keel would be a steel plate welded to a flat flange with the shape of the bottom.

[gonzo]

Stainless is a problem below the waterline because of crevice corrosion. Bronze or hot dip galvanized are better. For a built-up keel just epoxy glue it together. The keel bolts will go through everything anyway.

[Rocco]

Hi Gonzo,
I wish to thank you for your assistance. I can now start turning my dream into reality. I see you come from Wisconsin USA. In contrast, I live on the tiny island of Malta in the Mediterranean. The first time I saw Petrel Plans was in an advert of Naval Architect Percy W. Blandford way back in the mid seventies.
Thanks again
Rocco

Stainless is a problem below the waterline because of crevice corrosion. Bronze or hot dip galvanized are better. For a built-up keel just epoxy glue it together. The keel bolts will go through everything anyway.

[Burkie]

Hi Rocco,
I happened to post another query about Petrels,as we sail them here in Dungarvan Co Waterford ,Ireland,they were originally a design taken back from the US in the late 50's there were at least 50 of them built here ,mostly plywood ,then fibreglass.

There was no problem with the centreboard boxes once they were securely fixed,they were made of 3/4 inch ply but now the fact that uou can epoxy inside before assembly makes them perfect,the only thing is to use some types of bracket at the aft of the CB box & maybe stainless brackets midways.

The only other caveat is that the shape & size of the CB need to be altered,the blade is very wide front to back ,so if it was narrowed and made longer ,your boat would sail better & react faster,check the size of a Wayfarer CB. The other thing is that having a narrower CB there is more room between the CB box and the boom when tacking to get from one side to another,they narrowed the CB's here but didnt lenghten them ,so the boats made leeway.
I'll try & post some pics.
I have just renovated a fibreglass one & now me & abuddy are renovating an old ply one.
If you are a new build ,use epoxy & woven roving overlaid with straight weave on outside of hull with plain weave inside & you can make if of 1/4 inch ply as a stitch & tape method.
I could make real size patterns from our one & send them to you on paper templates if you like I also have a few modifications /improvements for your consideration.
Btw wehad four Petrels out sailing this evening there are only about 10 to 12 left in total now.

Regards

Eugene

[Burkie]

Hi Rocco ,just saw that the thread is a few years old,I'd still be interested in how you got on & if you had any pics.
we might have an international event !!

Eugene

[jmskydancer]

Burkie, you alive? I am building Petrel now. Can we get in direct contact somehow?

[Burkie]

Hi JM,
I sent you an email last week,glad to hear that you are building a Petrel,theyre a great boat. Very safe,good fun,will get up to good speed & will also plane & also a great family day boat.
I was out sailing in one yesterday afternoon in Force 5 to 6 winds -up to 28kmph We had her planing & nearly got it surfing on the larger waves.

As I think I said already I was going to build one myself & had all the research on materials etc & new building methods ready ,when I got a gift of a clinker-lapstrake- 1953 classic sailing dinghy to restore & I was doing that last summer,( launched in August) so I now dont need my own Petrel,I have the use of three of them at any time anyway.

Basically the CHEAPEST,EASIEST & STRONGEST way is to make the frame patterns out of old plywood-12mm will do.
Then mark out your panels & fit as per plans & stitch & tape them using nylon cable ties.

When the hull is complete & all the cable ties sanded off sheath the outside of the hull with BI AXIAL WEAVE 450 gsq M fibreglass cloth.
Ideally epoxy resin would be the best to use ,but for one tenth of the price you can use Polyester resin (marine grade) I can give you all the suppliers details & they post to Europe too.

Finish off the final coat of resin with a MICRO BALLOON powder additive for easier sanding ,then turn it over,REMOVE the plywood,fibreglass ALL the inside of the hull,fit a bulkhead forward of the mast,with detatchable panels,I'll show you how to do it ,then fit another bulkhead at the aft of the cockpit & fit a plastic lockable rectangular hatch in that.

At this stage you can alter the design by making narrower gunwhales ( side decks & fit a box type ply seat lower in cockpit or finish off directly down from side deck coamings to the floor ,& seal, then either finish will provide you with additional bouyancy.
The latter method is better if you are going to sail her hard as if you do capsize you take in less water & its easier to right the boat as well.
Get a second hand aluminium Fireball mast & make a 3 metre boom from timber,-EASY-
Will show you how
I can also give you details & pricelist for sails from "Hong Kong Sails" they're very cheap & use excellent materials,also they have a big range of colours too.
Other main factor is the centreboard size shape DONT use the original design,its not designed too well & it makes life akward for the crew tacking,I'll send you plans for one similar to a Wayfarer one & show you how to make it work.
This way you save a fortune on stainless steel screws & fittings as basicallly you have a composite plywood /fibreglass boat,the beauty of glassing all the plywood is that you dont have to use Marine Grade BS 1088 ordinary class 2 exterior grade will do fine & you save a load of time making & fitting frames plus the cost of materials,the stem can be laminated from strips of 10mm ply.
Let me know that you have received my emails & if youre on Skype I could talk to you.
All the best

Eugene

[Burkie]

Hi JM,

Have put post on forum,

Eugene;)