Fiber glassing over wood hull?

[p40warhawk1]

Hi all, I'm new to the forum and a first time scratch model builder. I am almost done with the basic hull shape and I would like to give it a smooth finish to stay true to the steal hull look and protect it from deteriorating over time. The hull is made of limewood planking. My idea is to fiberglass it however i'm not quite sure how to go about it. Are there any techniques or tips I should know about before diving in? Is there a better alternative to fiberglass over wood? Thank you! 

[allanyed]

Curtiss  (easier than p40warhawk1😀)  

First, WELCOME TO MSW.  Please post a little intro in the new member forum and mention your project as it may get additional responses.

 

Fiberglass saturated in resin can be applied but it will be the texture of fiberglass and difficult, if even possible, to give a super smooth finish.   

 

The following is not a great way to go for a one off, but will give you an idea of how fiber glass hulls are so nicely finished.  When fiberglass is used to make a hull it is done in steps.  The following is somewhat simplified but it should give you an idea of what is involved.  First is making a plug that matches the shape of the hull  (in this case, your model hull).  This is finished to super smooth surface than coated with a mold release wax.  This waxed hull/plug is then coated with gel coat and left to cure.  Once cured a thick fiberglass and resin coat is made, usually with some wood or other reinforcing so the mold will not flex later on.   Once the fiberglass resin is cured the plug is removed from the mold.  Next the mold is coated with a mold release wax.  Gel coat is then applied to the mold and allow to cure.  Last, fiberglass and resin is layered in an appropriate thickness and allowed to cure.  Once cured, the new glass hull is removed from the mold and the mold is ready for the next hull to be made.

 

For your purposes and to use the hull you have already made as is, some coating such as just gel coat might work or more simply why not fine sand the hull you have, then apply four or five coats of a good quality spray finish/paint?  There are wooden models with simple finishes that have been around for over 300 years.

 

I am sure there are members here that can give you the benefit of their own experience for simple yet effective way to get what you are shooting for.

 

Allan

 

 

 

Edited April 15 by allanyed

[Scottish Guy]

Hi @p40warhawk1, welcome to MSW and I hope this will be a great source for you to step ahead in your building. As for  fibreglass using for a hull I would advise not to use ot over wood. In general it is possible but requires some work and a lot of time. 

 

If you really want a fibreglass hull because of the smooth surface I would suggest to take Allan´s description, the process would be like with a real sail yacht, making a plug, mold for the hull and then build the hull by layering the fibreglass like a real hull would be build.

Fabricating fibreglass hulls is quiet an intense process, timewise and workwise. A lot of materials is required, an aired space and some really nasty materials and chemicals. Also a lot of steps when not experienced a lot of mistakes could sneak in which could ruin your plug, your mold or both.

 

I´m in the same shoes as you since i plan to copy a current luxury sail yacht as a model, I intend to create exactly the same what Allan described. The only difference is, I might use this method to create more than only one model, therefore the financial and work effort is worth it. Also I have experience with this process (even in a bigger scale - a real sailboat 24 ft and 38 ft) and it is hard work and will also be hard work in the smaller scale.

 

For getting the surface smooth of your wooden hall I would suggest planking and sanding or putty and sanding till you get the results you want to archive.

 

Micha

 

[Tschiller]

One easy way to fiberglass over wood is to do what RC aircraft builders have done. 

 

1) Make sure is sanded to the final shape and then fill any low areas and sand until it looks perfect.

2) Cover area using Nylons (yes women's hosiery). Cut it to fit and lightly stretch until any wrinkles or loose fabric is taught and then glue using Thin CA to secure to the hull (you only need to glue at various points to hold the fabric to the hull). It will take more than one piece so you may have to overlap slightly to ensure complete coverage.

3) Mix you Fiber Glass resin (practice with a small amount at first to determine how fast it hardens to determine how much you can work with at once). Use a scrap piece of card to apply resin onto fabric, work it into the fabric to ensure that all air bubbles/pockets are worked out and the fabric is laying flat against the wood and get surface as smooth as possible. Let resin set up.

4) Add a second coat of resin over the dried first coat and allow to fully cure.

5) Sand the resin being careful not sand through t nylons, this will show areas where the resin maybe low and require additional coats of resin. If you sand into the nylon you will need to recoat that area with resin.

6) Once you get a decent smooth surface you can fill any small pinholes or imperfections with an Auto body Glazing Putty and sand them smooth.

 

 

 

 

[Scottish Guy]

10 minutes ago, Tschiller said:

1) Make sure is sanded to the final shape and then fill any low areas and sand until it looks perfect.

 

I get where you are going, but do you not think this is wasted time and material? I can smoothen wood the same way as I could do fibreglass, just with a lot less work and effort. Especially when using putty which would be the same as using putty in the first place with the wood?

 

Micha

[Tschiller]

10 minutes ago, Scottish Guy said:

 

I get where you are going, but do you not think this is wasted time and material? I can smoothen wood the same way as I could do fibreglass, just with a lot less work and effort. Especially when using putty which would be the same as using putty in the first place with the wood?

 

Micha

Hi Micha,

 

I wouldn't do fiberglass on a static model, the only added benefit is durability from dings and such which are not a normal problem for static display.

[Scottish Guy]

11 minutes ago, Tschiller said:

I wouldn't do fiberglass on a static model, the only added benefit is durability from dings and such which are not a normal problem for static display.

 

Hi Todd, then we are somehow on the same route. For my scratch model I only would use fiberglass because the origin is made of fiberglass and I want it as authentic as possible and I maybe will do more than one copy of it (depending on the outcome - how accurate and authentic the model becomes).

 

Micha

[p40warhawk1]

On 4/15/2024 at 2:03 PM, allanyed said:

Curtiss  (easier than p40warhawk1😀)  

First, WELCOME TO MSW.  Please post a little intro in the new member forum and mention your project as it may get additional responses.

 

Fiberglass saturated in resin can be applied but it will be the texture of fiberglass and difficult, if even possible, to give a super smooth finish.   

 

The following is not a great way to go for a one off, but will give you an idea of how fiber glass hulls are so nicely finished.  When fiberglass is used to make a hull it is done in steps.  The following is somewhat simplified but it should give you an idea of what is involved.  First is making a plug that matches the shape of the hull  (in this case, your model hull).  This is finished to super smooth surface than coated with a mold release wax.  This waxed hull/plug is then coated with gel coat and left to cure.  Once cured a thick fiberglass and resin coat is made, usually with some wood or other reinforcing so the mold will not flex later on.   Once the fiberglass resin is cured the plug is removed from the mold.  Next the mold is coated with a mold release wax.  Gel coat is then applied to the mold and allow to cure.  Last, fiberglass and resin is layered in an appropriate thickness and allowed to cure.  Once cured, the new glass hull is removed from the mold and the mold is ready for the next hull to be made.

 

For your purposes and to use the hull you have already made as is, some coating such as just gel coat might work or more simply why not fine sand the hull you have, then apply four or five coats of a good quality spray finish/paint?  There are wooden models with simple finishes that have been around for over 300 years.

 

I am sure there are members here that can give you the benefit of their own experience for simple yet effective way to get what you are shooting for.

 

Allan

 

 

 

Thank you for the response Allan, I like the Curtiss name! I’ll be sure to write an introduction soon. I’m starting to lean towards not fiberglassing since it is only a static model. My only concern is having a wood grain texture under the paint but I’m sure fine sanding it will solve that problem. Thank you for the input! 

[p40warhawk1]

On 4/15/2024 at 2:37 PM, Scottish Guy said:

Hi @p40warhawk1, welcome to MSW and I hope this will be a great source for you to step ahead in your building. As for  fibreglass using for a hull I would advise not to use ot over wood. In general it is possible but requires some work and a lot of time. 

 

If you really want a fibreglass hull because of the smooth surface I would suggest to take Allan´s description, the process would be like with a real sail yacht, making a plug, mold for the hull and then build the hull by layering the fibreglass like a real hull would be build.

Fabricating fibreglass hulls is quiet an intense process, timewise and workwise. A lot of materials is required, an aired space and some really nasty materials and chemicals. Also a lot of steps when not experienced a lot of mistakes could sneak in which could ruin your plug, your mold or both.

 

I´m in the same shoes as you since i plan to copy a current luxury sail yacht as a model, I intend to create exactly the same what Allan described. The only difference is, I might use this method to create more than only one model, therefore the financial and work effort is worth it. Also I have experience with this process (even in a bigger scale - a real sailboat 24 ft and 38 ft) and it is hard work and will also be hard work in the smaller scale.

 

For getting the surface smooth of your wooden hall I would suggest planking and sanding or putty and sanding till you get the results you want to archive.

 

Micha

 

Thank you Micha! I think y’all talked some sense into me. I’ll be planking, puttying, and sanding. Thank you for the input and good luck on the yacht!