World Sea Fishing Forums banner
1 - 11 of 11 Posts
G

·
Discussion Starter · #1 ·
Anyone on here good at making fiberglass construction etc?

I need a new engine box for my inboard and have been quoted 250 QUID! is that a good price or not?

It is a pretty standard engine cover, 4 sided in white with just a base rim and approx 700m/m wide x 650m/mhigh and 950m/m long.

Is it easy to do myself? I do lots of my own fiberglassing on the boat but never worked with any that did not have to be painted or with flo-coat etc.

I want it white gel coat and not painted if possible.

I suppose delivery is an issue as well if made by someone so anyone know of a builder local or does anyone on here want the job for cash?
 

·
Registered
Joined
·
1,528 Posts
Is your desire for GRP engraved in stone? Because for an engine box it does not have a great deal of sound deadening affect. If you were to make a GRP box you would still have to make a mold to lay it up in, so why not forget making a mold and just go straight into making a box from marine ply? The carpentry is easy, and the sound deadening of half inch ply is good and bloody good if insulated with low density fiber board on the inside. The disadvantage of wood however is weight, probaly 50% more than GRP. On the other hand the advantage is price, probably only 20% of what you were quoted for a GRP cover.

Afishionado
 

·
Registered
Joined
·
45 Posts
Anyone on here good at making fiberglass construction etc?

I need a new engine box for my inboard and have been quoted 250 QUID! is that a good price or not?

It is a pretty standard engine cover, 4 sided in white with just a base rim and approx 700m/m wide x 650m/mhigh and 950m/m long.

Is it easy to do myself? I do lots of my own fiberglassing on the boat but never worked with any that did not have to be painted or with flo-coat etc.

I want it white gel coat and not painted if possible.

I suppose delivery is an issue as well if made by someone so anyone know of a builder local or does anyone on here want the job for cash?
Why not make the box out of 1" insulation board then fiber glass both sides! its easy to make and lay up in grp also very light, all products available from Atlantic cladding
 

·
Registered
Joined
·
5,557 Posts
Too far away to make it for you but here is how I would do it.

Make up the box out of 12mm WBP ply and edge joint it with 30mm No7 screws and Balcotan glue. When the glue has gone off do a trial fit to make sure the box is right and there is room inside for insulation. Remove the screws and radius over all the external edges and corners.

Resin the inside of the box and add CSM mat cut into 6 inch wide strips to reinforce the joints, use the strips like tape, then resin the inside again and cover the whole inside of the box in CSM mat.

On the outside of the box resin it and roll in 2 layers of CSM. Lap each layer around the botton edges of the box and onto the inside by a couple of inches. If you have to join the CSM don't cut it you will get a hard line, rip it and it will blnd into the next sheet without leaving a visible joint.

Go over it with a layer of surface tissue and you should have a reasonable surface for your flocoat. It won't be as smooth as a cover made in a mould but will look presentable. If you put the flocoat on thick you could sand it back to get a flat finish with progressively finer grades of paper finishing off with Farecla, G3 and then G10.

Put some fireproof insulation on the inside to provide some sound insulation.

As a safety matter you may want to leave room on the height of the box to add an automatic extinguisher.
 
G

·
Discussion Starter · #6 ·
Thank you all for your speedy and helpful replies.

I had thought of wood but as a rule I try not to use wood anywhere on my boats if at all possible, in fact when I get a boat my first job is too remove as much as possible and replace it with plastic or grp - it's just the maintenance thing, in the end wood will beat you and get old / rotten etc and my trade is plastics so its where my expertise lie.

The initial thought of grp was firstly weight and second to look smart, I have put a lot of work and money into this one so want it to look as nice as possible and of course I will be selling it on in a year or 2 anyway.

I am trying to keep weight down wherever possible for obvious reasons (I've gone to great lengths and cost to get speed)

I know I could make one "over" a wooden box or template but don't know if I could really get a nice finish, however Chris what you describe appears to be ok as long as I can sand it to a good finish in the end and the outside (flocoat) was white.

Sound is another major issue, this new engine I have built is a transit diesel! and we know what they sound like at the best of times and this one is mega tuned as well! so sound insulation is what I have planned anyway and have found some really good products on the net.

So, a few stupid questions:
CSM = chopped strand matting?
Flo coat = what is this, coloured gel coat?
Balcotan glue = never heard of it?
Farecla, G3 and then G10 = again explain?
How would 2 walls of say 1/4" ply with a cavity be for sound proofing?

Thanks for the help guys, very good as always.
Steve
 

·
Registered
Joined
·
2,806 Posts
do as cris says then sand down and finish with 1200 wet and dry, then take it to a car spray shop and for a few quid the will apply rupping compond (Farecla) and buff it for you, it will shine like a six pence up a sweeps arse
 

·
Registered
Joined
·
5,557 Posts
CSM = chopped strand matting?

Yep, comes in meter wide rolls, randomly arranged glass strands bonded with styrene to make a workable sheet with strength in all directions.


Flo coat = what is this, coloured gel coat?

It is gel coat but with added wax


Balcotan glue = never heard of it?

It is a moisture cure polyurethane glue which is waterproof, it sticks like cack to a blanket, foams slightly on cure to fill small voids and does not blunt tools when being worked. Brilliant stuff but don't get it on your hands, it doesn't come off.


Farecla, G3 and then G10 = again explain?

G3 is a coarse cutting paste for machine buffing and G10 is a finer finishing compound formulated for use on GRP laminate. (good stuff)


How would 2 walls of say 1/4" ply with a cavity be for sound proofing?

Not a acoustic expert but I would think it is too thin and would form a sounding board. If there was a dead air space between the 2 boards I would guess it will transmit the sound. Plus engine covers inevitably become seats and need to be strong, I doubt 1/4" ply would be strong enough unless it was covered with 4 or 5 layers of CSM and had ribs built in to the underside to privide rigidity.
 

·
Banned
Joined
·
820 Posts
Thank you all for your speedy and helpful replies.

I had thought of wood but as a rule I try not to use wood anywhere on my boats if at all possible, in fact when I get a boat my first job is too remove as much as possible and replace it with plastic or grp - it's just the maintenance thing, in the end wood will beat you and get old / rotten etc and my trade is plastics so its where my expertise lie.

The initial thought of grp was firstly weight and second to look smart, I have put a lot of work and money into this one so want it to look as nice as possible and of course I will be selling it on in a year or 2 anyway.

I am trying to keep weight down wherever possible for obvious reasons (I've gone to great lengths and cost to get speed)

I know I could make one "over" a wooden box or template but don't know if I could really get a nice finish, however Chris what you describe appears to be ok as long as I can sand it to a good finish in the end and the outside (flocoat) was white.

Sound is another major issue, this new engine I have built is a transit diesel! and we know what they sound like at the best of times and this one is mega tuned as well! so sound insulation is what I have planned anyway and have found some really good products on the net.

So, a few stupid questions:
CSM = chopped strand matting?
Flo coat = what is this, coloured gel coat?
Balcotan glue = never heard of it?
Farecla, G3 and then G10 = again explain?
How would 2 walls of say 1/4" ply with a cavity be for sound proofing?

Thanks for the help guys, very good as always.
Steve
"it will shine like a six pence up a sweeps arse" :clap3:

Really? That shiny? :g: :)
 
G

·
Discussion Starter · #10 ·
Cheers Guys, good fast replies again.

I have enough info to do a job now,
Thanks for the explanation Chris!
 

·
Registered
Joined
·
9,541 Posts
Just by way of encouragement, I built a battery box as my first ever GRP job (other than repairs) in the same way as ChrisP has described, although as it was just functional I finished it with a couple of coats of resin and did not bother with the tissue or rubbing down. It was very quick, very satisfying and a lot easier than I was expected.
 
1 - 11 of 11 Posts
Top