Tengu and the Boat

[Tengu]

Well, this recent weather in odd directions has put things in odd places.

The result of this is I now am the somewhat perplexed owner of a pram dinghy.

Its a fibreglass thing which has been used as a vehicle for many paint jobs.

Who would think a simple craft could be so much trouble? But I have a lot of questions.

-How do you remove paint from GRP?
-If I find a random bit of plywood, how do I tell what grade it is?
-How do I join wood that will take strain? I have got some 2x1 to make oars with. I am going to laminate it up with good quality epoxy but should I add screws?

 

[Toddy]

What size of oars/paddles do you need ? There's a set of plastic ones on aluminium handles in one of my sheds. They were meant for one of those blow up boats.
They could probably come down by courier.

M

 

[snappingturtle]

I don't know of any striper that is ok with the gel coat or not, I would try using a plane blade and linish the paint off as close to the finale paint coat, then sand, as for ply all the sheets I used came from a reputable supply you should be able to steam it to take on a new shape and it will set well to its new form, and for joining I used exstrafen / cascamite (sp) glue and graded SS screws.

 

[Tengu]

Thanks Toddy, but they would be too short, -rule of thumb for oar length is beamx2 so for me that is 8ft.

 

[Fraxinus]

Paint removal on GRP:- depends on the paint but you need to make sure not to sand through the Gelcoat that is an epoxy based coloured skin over the fibreglass that keeps water out.(often plain white).
Polyurethane glue (gorilla glue is a trade name) is sufficient to laminate up paddles and oars if you keep them well oiled or varnished, the wood needs to be fairly free of weak spots like knots so most are made from Douglas Fir or similar that has good knot free lengths.
The plywood question is way harder, the only real difference between WBP ply and Marine ply is that Marine ply is guaranteed to be free of voids in the laminations.
As my boat building mentor put it "when there is only 3/8ths (9mm) between you and 'Davy's locker' you want it to be more than 2/8ths (6mm) of air".
Don't cheap out on the ply quality if it is structural unless you can see the stamp in the corner that states what it is.
Rob.

Edit : meant to mention screws not required in oar making and the Polyurethane glue is way cheaper than epoxy if you don't already have some to hand.

 

[Toddy]

Thanks Toddy, but they would be too short, -rule of thumb for oar length is beamx2 so for me that is 8ft.

Ah, I think these come in around the six foot.
I do have other oars, but they're craftsman made, leather wrapped where they sit in the rowlocks, and copper tipped. I'm not for offering those.
Best of luck finding something suitable.

M

 

[Tengu]

Thank you. no, its not load bearing. I want it for oar blades

 

[daveO]

Is it the type that you can fit a mast and sail to? I always fancied a go in one of those as a kid, they look like a lot of fun. I've seen a few fitted with those old Seagull outboard motors too. The ones that you had to start through a secret combination of swear words and blood sacrifice and would only run until you got into the main channel and then they'd stop suddenly to give you a go at rowing into the current. I think my dad still has one somewhere but he's given up swearing so it probably won't start anymore.

 

[Toddy]

daveO you have no idea just what memories that all brings back
I think my bother still has the old Seagull buried in a workshop somewhere.

M

 

[daveO]

daveO you have no idea just what memories that all brings back
I think my bother still has the old Seagull buried in a workshop somewhere.

M

More importantly does he still have all his fingers?

 

[Toddy]

Aye, he does, but I mind seeing scars on someone else's hand. I also mind ours having to be grapnelled up from the bottom of the Gare Loch at one point too.
I mind seeing him standing in utter awe in front of a "dirty big kelvin" and the look of longing was almost cartoon like. Now that was an engine

M

 

[Alan De Enfield]

A few years ago a friend who was a senior REME armourer was 'requested' to go and assist in the clean up of the Normandy beaches.
Amongst all the unexploded ordnance they came across was a crate of Seagull OB engines, they took them back to the workshops, washed them down removed 70+ years of sand, changed the oil in the gearbox, added fuel, changed the plug and they ran "like a good 'un".

The problem with Seagulls was the petrol / oil mix some of the early models were 12:1, later ones went up to 25:1 and just before production ceased they managed to get it up to 50:1.
It cost almost as much in 2T oil as it did in petrol.
Superb reliable back-up engines.

 

[Toddy]

I think that was the problem. All those old soldiers and sailors had it in mind that the Seagulls were really good reliable engines.....until the 1960's and 70's when they were carnaptious, unreliable, unlovable, underpowered carp.

M

 

[Tengu]

That sounds terribly luxurious, to have an outboard.

As much as being able to have a yacht with its very own bell...

 

[Tengu]

How do you use polyurethane glue? I am not familiar with it.

It is going to get sails eventually...and leeboards

 

[daveO]

That sounds terribly luxurious, to have an outboard.

As much as being able to have a yacht with its very own bell...

It's the height of luxury. I rock a Mercury 2.2hp, it's a beast. That paddle is just for show (ok for regular emergencies )

 

[Toddy]

That paddle looks awfully familiar

 

[Fraxinus]

How do you use polyurethane glue? I am not familiar with it.

It is going to get sails eventually...and leeboards

Any ply will do for oar blades if well varnished and now I understand the oar type yo're looking at then brass or stainless screws for fixing the blades onto the shaft.
P.U glue is easy to use, just like PVA but it uses moisture to cure so a damp rag wipe over the joint faces will help. It foams and expands as it cures too so smear it on thinly.
It also takes ages to clean of your skin so wear disposable gloves unless you have acetone at hand.
When cured the foamy bit can be scraped off or sanded.
Rob.

 

[Tengu]

Thanks for the advice Fraxinus, growing up a modelmaker I learned how to use all sorts of glue...But this one is new to me.

It always annoys me when I see cag handed glue jobs...I can even stick rear mirrors to windscreens! (Tip, there is a special pad at the motor shop)