Taking out window & replacing with porthole on NB with fibreglass sides

[Mitchellmoxo]

Hello,

 

The sleeping area of my boat is now at the front where there is dobule windows on each side + the front door and a window on the front bulkhead. I would like to replace the side windows with some portholes however taking the windows out will leave a much bigger gap than the porthole.

 

Does anyone have any ideas on how to fill such a large gap so I can replace the window with a porthole?

 

Kind Regards

Mitch

 

Edited September 22, 2015 by Mitchellmoxo

[Mike Tee]

http://www.kedianengineering.co.uk/index.html

Try this

[Mitchellmoxo]

I know of Martin as I had my boat overplated by him the boat in question is actually on the website at the bottom. However my boat is a fibreglass top & he is a metal fabricator. I would like to do it myself anyway to save costs just asking for the best way to do it.

 

Thanks

[Neil Smith]

If you take the window out then cut a piece of plywood a bit bigger than the hole and gripper it on the inside then you can laminate and gel coat over the outside then paint it, now mark out your port hole cut out with gig saw and fix it.

 

Neil

[Mitchellmoxo]

I am just worried that the point where the old window cutout and the new fibrelass will crack over time is there any proper method of bonding the 2 new edges together so it wont crack

[Sea Dog]

Mitch, your boat looks quite tidy in the photo, albeit with a window where you'd prefer to have a porthole. I think it unlikely you're going to make such a drastic change without making a bit of a dog's breakfast of it. Just my 5 cents.

[W+T]

I did a similar job but i replaced all the windows with new ones and added different ones to the front, much in the same way it would work for yours.

 

here is a link to the build blog on here.

 

. http://www.canalworld.net/forums/index.php?showtopic=76076&hl=

[Mitchellmoxo]

Hello, I actually thought of you when posting this up as I had read your blog on here previously so thanks for the reply. How are you filling the gaps on the outside once layering up the fibreglass on the inside? my boat sides are about 12-15mm thick as there is fibreglass then a thin layer of insulation foam then fibreglass on top, what would be your thoughts on how to fill this void?

 

thanks very much

[W+T]

Hello, I actually thought of you when posting this up as I had read your blog on here previously so thanks for the reply. How are you filling the gaps on the outside once layering up the fibreglass on the inside? my boat sides are about 12-15mm thick as there is fibreglass then a thin layer of insulation foam then fibreglass on top, what would be your thoughts on how to fill this void?

 

thanks very much

 

I will go in steps to make it easier

So yours is a sandwich construction, in that case i would do as i have with mine for the outer skin, i would use either perpsex sheet or hardboard, this will give a nice and very smooth finish on the outside, Then i would cut the hole for the port hole, then get the insulation the same thickness or as near as possible to the original thickness and use a good adhesive to stick that to the out skin just made, Then lay up the inner skin onto the new insulation and bn it in well to the old grp edges.

 

Always chamfer back the edges you and laminating to to get a good seal/bond, and use plenty of acetone to clean just before you lay up. The hole that you will need to drill for the screws to hold the moulding sheet in place ( the perspex/hardoard ) can be filled once chamfered with car body filler, as can any imperfections that will...mite arise in the new outer skin to old skin.

 

To get a good level join use battens all around the aperture egde to pull the perspex tight close, oh and dont got the Blue to release the perspex Done that once and i wont do it again

 

 

 

I hope you understand that, if not ask what you dont understand and i will try again, not much good at expalining some times.

Mitch, your boat looks quite tidy in the photo, albeit with a window where you'd prefer to have a porthole. I think it unlikely you're going to make such a drastic change without making a bit of a dog's breakfast of it. Just my 5 cents.

 

 

Like to vote of confidence there lol.

[Mitchellmoxo]

Hello,

 

Thanks so much for the detailed reply I really do appreciate you offering your expert advice on here. I understand the process and how I can do it but still have a few questions if thats ok.

 

1. when I have screwed the perspex into place and start building up my first layer do I build up a thick layer of resin first so it gives a flat finish or just apply resin as normal and bed in the glass

 

2. how many layers of material shall I do on each side of the sandwich?

 

3. did you use any form of releasing product etc on the inside of the perspex so you could remove it easily when finished?

[Murflynn]

I would not even try to make a seamless infill piece, instead I would make a feature of it, with an inset recessed panel of plywood/GRP (fixed inside the cabin side), into which I would fix the porthole. As long as the porthole is centred on the infill panel it will look as if it was intended to be that way.

[Mitchellmoxo]

Great idea but as I am a fussy git I know that doing this would bug me to the point of me starting again and doing it so the sides are flush anyway lol!! If I could do this so there was a constant recess all the way along like on some I probably would of done it

[W+T]

Hello,

 

Thanks so much for the detailed reply I really do appreciate you offering your expert advice on here. I understand the process and how I can do it but still have a few questions if thats ok.

 

1. when I have screwed the perspex into place and start building up my first layer do I build up a thick layer of resin first so it gives a flat finish or just apply resin as normal and bed in the glass

 

2. how many layers of material shall I do on each side of the sandwich?

 

3. did you use any form of releasing product etc on the inside of the perspex so you could remove it easily when finished?

 

 

Morning, and thank you for the comment ` expert advice` i am far from an expert at anything but drinking Cider very expert at that

 

Now then

 

1 . You can either use Gel coat and tissue matting then let set then resin and CSM and so on to get the thickness you need, three laminations of 450grm CSM will give roughly 5mm thickness. Or as i do most the time now and that is wet out with resin then tissue, resin, CSM etc again same as with the Gel coat but no Gel coat, if you see the transom i have done it got a glass finish as with Gel coat, even the bow repair ans all other repairs i have done.

Using Gel coat is the way most folk go about it, and the PROPER way,

 

2 . As in Q1, three layers of 450grm will give about 5mm finished thickness, but if the thickness is say 10mm do just 3-4 layers of 450grm and just before or as its going green ( not long maybe 5-10 mins ) do more the the thickness you want, you dont want it setting to quick really. So depends on the thickness of the shell sides, i generally always use 450grm so i know how thick it lays up, not sure with 350 or 650 grm.

 

3 . Apply at least to two coats of PVA Mould release agent, the blue stuff i mention. You can use a wax but you need to polish it on a few times and this PVA is easy and good stuff, when you come to release the perspex just add water, luke warm if you can and it will dissolve the Blue and come away with the help of a wedge or as it is flat may be just peel off.

 

Hope that helps

Edited September 23, 2015 by W+T

[Mitchellmoxo]

Hello mate. Thanks for the reply and info again really appreciated I brought a 5kg fibreglass kit + release agent today so will get started on that as soon as it arrives! No place round here that seem to sell it? Do you know of any shop chain that sell it in bulk like that? I know halfords sell it but 4x the price I paid for this kit on eBay!

 

Regards

Mitch

[W+T]

Hi Mitch, i get mine from a local place, no cheaper to buy but saves on postage and only 20 mins away so i can colelct it, but there are some good palces that do it, i have used both and and both good.

 

http://www.glasplies.co.uk/

 

http://www.ecfibreglasssupplies.co.uk/default.aspx

 

 

and another

 

http://www.cfsnet.co.uk/

Edited September 23, 2015 by W+T

[Mitchellmoxo]

Thanks for the links, i paid £59 for a 5L resin with hardener and 5 sqm of fibreglass matt does that sound about right? Hope your project is going well!

[W+T]

Dont sound to bad that mitch. I pay £87 for 20kg resin and 5kg 450grm CSM

Dont forget tissue. Need that to make sure you get a smooth finish.

Boat is coming along ok. Selling my car to fund it now lol. But ss of 5mins ago my laptop fell apart. Thank god I have my phone to use for now. More money out the boat fund now:(

[Mitchellmoxo]

hi mate didn't realise fibreglass was so expensive until today!

 

I actually forgot the cloth - oops, that leads me to 1 more question (sorry!)

 

Do I wet the acrylic sheet from the inside and then put the cloth in while the resin is still wet or do I first paint a layer of resin on the inside let it dry and once its dry then start layering up the fibreglass starting with the layer of cloth? Also I assume when layering up the fibreglass you do it all at once rather than letting it cure between layers so it bonds together?

 

Appreciate you sharing your advice I would not of been comfortable starting this part of the project without your advice. I am a signmaker by trade so if you would like me to print your boats name for you out of vinyl and post it I would be more than happy to do so as a return of favour! just pm me if so

 

Regards

Mitch

[W+T]

Morning Mitch. Dont mind helping out if I can.

If using Gel coat then put that on and the tissue while gel is wet. Then let go tacky. Then lay up.

If not using gel coat wet out with resin add tissue and more resin and straight away lay up, dont let that set first.

kind offer for the boat name. Still not fully decided though on the name. Either Wet Dreams orJolly Wolly. I like Wetdreams butT likes Jolly Wolly.

[Mitchellmoxo]

Morning,

 

You wake up early! I dont think I will be using gel coat I will do it the same way you have done. So you wet out with resin and apply tissue straight away rather than letting it set first? Then start laying up straight away?

 

Cool no probs well the offer is there when you want them!

 

ETA - I just cancelled my fibreglass order from eBay and re ordered from MB fibreglass supplies. I paid £84 for 10sq m 10kg fibreglass kit, 5 sqm of tissue, 1L of PVA release agent and 5L of acetone. Pretty good price I think considering I paid £59 for just a 5KG kit before!

Edited September 24, 2015 by Mitchellmoxo

[W+T]

Hi Mitch, up for work at 3am

yes wet out from the start. I always use that little bit more on the wet out before the tissue is layed

did you get a roller for rollling in the matt.easy than dabing with a brush and easier to get the air out.

 

oh that is a better price for the gear. Good to shop around

 

Just dont mix much resin 1litre max with 10ml of catalyst. That will start to gel in about 15-20mins in air temps now.have 3tubs filled with resin also ready to add the cat as you go.

Edited September 24, 2015 by W+T

[Mitchellmoxo]

Hi mate 3 am rather you than me! Didn't get a roller will order one tomorrow.

 

When you wet out do you let the resin set before laying the tissue?

 

Good tip for having the tubs ready will use that one!

Edited September 24, 2015 by Mitchellmoxo

[W+T]

Yes but I have finished work and home before 2pm . Time to play out then

Yes dont let anything set. If the resin in the pot starts to gel then leave it and go onto the hext tub.

Oh and plenty of gloves and acetone.

And we want pics step by step lol. When I am doing it just get it done. Sod pics but I want to see if you can without the steaming ahead before resin sets lol

[Mitchellmoxo]

Pics I will try! Once again thanks for all your help much appreciated

[Mitchellmoxo]

Yes but I have finished work and home before 2pm . Time to play out then

Yes dont let anything set. If the resin in the pot starts to gel then leave it and go onto the hext tub.

Oh and plenty of gloves and acetone.

And we want pics step by step lol. When I am doing it just get it done. Sod pics but I want to see if you can without the steaming ahead before resin sets lol

 

 

Pics! Had some teething problems at the start lol I tried the cup method but the resin kept burning through the disposable cups!! Ended up using 1 jug and pouring in same amount every time + a couple of other bits that went wrong but to be expected when you are trying something new!!

 

 

 

Board over the perspex panel to keep it stiff

 

 

view from inside with PVA blue release agent

 

 

1st lot of fibreglass (1 layer of tissue + 3 layers of 450gsm)

 

 

board to be sandwiched in between

 

 

final layer of fibreglass over the board. I only used one for now will see how strong it is when I go back there next and may add another if I need to.

 

 

 

Ready for some filling & painting

 

 

I have learnt so much about working with fibreglass today and from what you have taught me! My head is banging from the fumes lol even though I had the front and rear doors open all day. Thanks for much for your help again mate.

Edited September 28, 2015 by Mitchellmoxo