1949 Chris-Craft 19' Racing Runabout by gjdale - FINISHED -Dumas - 1:8 Scale - RADIO

[Keith_W]

That test piece looks fantastic. Thank you for showing us the process. I'll keep that at the back of my mind if I ever attempt a model like this. 

[donrobinson]

Thanks a lot for showing that, looks like it will be a good finish on your boat. Please keep us updated

[src]

Grant,

That looks VERY good! You mentioned SIntra as a sub deck, what did you use to bond the decking to the SIntra?

Sam

[gjdale]

Thanks Sam. I used thick CA to bond the planking to the Sinatra. It required a LOT of kicker! That's just one more reason to coat the whole thing in a fibreglass jacket - I don't really trust the CA bond strength over time. If I were to do this build again, I would replace all the Sinatra subplanking with timber - either light plywood sheeting or balsa strips. The Sinatra is supposed to be a weight saving, but I think it introduces more problems than it solves.

[mtdoramike]

What a step by step process on the glassing. But what a beautiful finish. I can't wait to see the final result.

 

 

 

mike

[gjdale]

Thanks for all the kind comments and the likes. It's been a while since I updated this, but not because I haven't been making progress - it's just that this is a slow process!  Anyway, here is a little update of sorts.

 

Fibreglassing the Hull

 

Having declared a win with the trials, I commenced the process of glassing the entire boat. Although the instructions say not to bother glassing the bottom of the boat as it is plastic (Sintra), I decided to take the precaution of glassing it anyway.

 

This is a slow process overall as it is necessary to work on only one surface at a time and to allow it to fully cure before proceeding to the next surface. Here is a couple of in-progress shots of the first phase – applying the glass mat with the first layer of epoxy resin. It followed much the same path as the trials (happily).

 

I began with the bottom, cutting the glass mat slightly larger than required. In hindsight, I could have trimmed this much closer prior to applying the epoxy. The resin was applied by pouring a small amount into the centre and spreading outwards with a rubber squeegee. Care needs to be taken to avoid any drips landing on the overhang and sticking itself to the hull sides – don’t ask how I know this!

 

 

The sides were next:

 

 

Here is a close-up of the side, showing just how much of the weave of the cloth is visible at this stage. Remember, trust the process!

 

 

Once the epoxy had cured (overnight) the cloth was trimmed back using a single edged razor blade:

 

 

It’s not clear in the above photo, but I found that with a little caution I could run the blade right along the adjoining edge, making final clean up with some 80 and 120 grit sandpaper that much easier.

 

Speaking of clean-up, this next shot shows the side after it had cured, been trimmed and lightly sanded with both 80 and 120 grit. The purpose here is to remove any high spots and create a smooth (but toothed) surface for the next layer of resin.

 

 

As you can see in this photo, it looks pretty ugly. There were quite a few “blemishes” where the cloth may have lifted slightly during the initial coating. Remember, trust the process!

 

Once both sides had been done, the transom followed, and finally the deck. All went pretty much as shown in the above photos, though perhaps with fewer flaws as I gained experience.

 

Then it was time to apply the second layer of epoxy. Again, it was a case of doing just one surface at a time, keeping that surface as horizontal as possible to allow the resin to level and not overflow the edges.  As per the trials, the second coat was applied with a stiff brush, care being taken to ensure that the “oopses” from the first phase were filled in by firmly stippling the area with the brush until the oops disappeared.

 

I didn’t take any “in-progress” shots of individual panels, but here are a few on completion of the second coat of epoxy. At this stage, the epoxy has fully cured but no clean up sanding has been done. This will be carried out prior to applying the third coat of resin. However, I thought it useful to post these overall pics to show just what a difference the second coat of epoxy makes. It has almost entirely filled in the weave of the cloth and the “shiny-ness” gives an indication of what is to come.

 

 

 

 

It’s very difficult to take pictures of a highly polished and reflective surface, but I think you can get the idea. And yes, you can see a slightly uneven “wavy” effect on the surface – this will come out with the between coats sanding. Hopefully, one more coat of resin will be sufficient prior to commencing the finish coats of spar varnish. If not, we’ll keep going until it is!

 

It will be a little while before the next update as I'm travelling for work over the next couple of weeks.

 

[PamW]

For doing fiberglass. ..look into stuff called peel ply......it is placed on top of wet glass and squeegeed. Let dry...then "peel" off......leaving a completely smooth surface where very little if any sanding and/or filling are required.

 

Pamela

[Keith_W]

That is stunning! I look forward to seeing your boat all sanded and shining like a little jewel. 

[gjdale]

Thanks for that tip Pam - though a little late to be used for this build.

 

I just had a quick look at the Peel Ply and while it looks good, it does have some limitations. I found this on one suppliers' site (http://www.clcboats.com/shoptips/epoxy_and_fiberglass/peel-ply-release-fabric.html):

 

"We’ve written before about the challenge of getting smooth surfaces with epoxy and fiberglass.  It takes at least three coats of epoxy to “fill the weave,” and then hours of sanding to get to a surface finish that’s ready for paint or varnish.

What if you could skip two of the three coats of epoxy and most of the sanding?  Well, you can.  Sometimes.

“Peel Ply,” also called “Release Fabric,” is a synthetic cloth that you drape over your epoxied surface as the epoxy sets up.  Once cured, you can peel off the fabric, and what’s left behind is a perfectly smooth surface that’s ready for a quick sanding, or for the next round of epoxy.  No runs, no sags, no low spots.
 
Not only is the surface under the peel ply nearly perfectly smooth, it actually has a texture that improves adhesion if you have anything else to stick to it.  We use it here whenever we can. 

Like all things, there’s a downside to this miracle.  Peel ply isn’t stretchy like fiberglass, so you can only use it on really flat surfaces.   Hatch covers, for example.  Or the components of a stitch-and-glue boat that haven’t been assembled yet, but which are pre-coated in epoxy and/or fiberglass prior to assembly. 

If you try to get peel ply to conform to curves, you might end up with wrinkles in the peel ply.  And the peel ply will cast those wrinkles in solid epoxy, leading to a horrifying sanding session."

 

Nevertheless, an interesting concept and useful tip thanks Pam. Maybe next time.....  

[mobbsie]

​Hi Grant,

 

Just checking in mate and WOW, she is coming along in leaps and bounds.

 

A wise move mate to treat the underside of the hull, bearing in mind who is going to be driving it. ( I would never dream of saying a thing like that mate, but I was told to by the boss, honest).

 

She morphing into a thing of beauty Grant, be very proud mate.

 

Be Good

 

mobbsie

[wefalck]

Does cling-film cling to epoxy resin ? No idea, but if it doesn't, you may be able to use it like 'peel ply' thing. I gather it works squeeze the resin flat, rather than following the contour of the woven fabric surface. Could be worthwhile some experiments.

[src]

Grant, that looks great. I never thought of using peel ply like Pam recommended. We use it when vacuum bagging complex parts and will be doing a second layup as, like mentioned, it leaves a texture for the next layer to adhere to.

Looking forward ti the final product.

Sam

[mtaylor]

Beautiful finish with the glass work, Grant.  And you're planning on varnishing after the glass work?  

 

Side note, I've used plastic trash bags like the peel and ply but only for the final coat unless it's multilayer glass or carbon fiber.  But I was also vacuum bagging as Sam mentioned.  It gives a smooth, shiny surface unless you get a wrinkle in the bag.  And no... I wouldn't think of vacuum bagging a wooden ship.  

[src]

 And no... I wouldn't think of vacuum bagging a wooden ship.  

 

Matchsticks and scrap bin.....

 

sam

 

[gjdale]

Beautiful finish with the glass work, Grant.  And you're planning on varnishing after the glass work?  

 

Thanks Mark,

 

This is only the second coat of epoxy, prior to sanding. It will get one more coat of epoxy (at least) to fully fill the weave of the cloth. Then another sanding followed by several coats of spar varnish, which will be sprayed on. After the epoxy and before the varnish, I will apply the vinyl artwork so that it gets sealed under the varnish, just like on the full size version.

[John Allen]

Grant,

 

Awesome! question a little late would chopped mat ( believe has a lot less weight)  have required less layers of resin, for my future reference?

[gjdale]

John,

 

Thanks for looking in, and for the question. The answer is, I have absolutely no idea! I don't understand why a chopped mat would be less weight - at 2oz. this cloth, while not the lightest available, is still pretty light. As for layers of resin, from what I've read (and experienced so far), three layers seems to be the common wisdom for "minimum" number of layers of resin: first layer to adhere the cloth to the substrate, second layer for general filling of the weave, third layer for final filling of the weave. Of course, more layers may be necessary, but I can't see fewer layers being used, unless using something like the method mentioned above by Pamela.

 

I have to say, that with two layers of resin so far, the hull feels nice and solid without feeling heavy.

[src]

John, I would think you would have less control using a chopped glass vs a manufactured cloth of a given weight per sq foot. In my experience the final weight and thickness of a part with chopped glass is dependent on the skill of the operator.  The shop I work at fabricates a lot of fiberglass parts both with chopped glass as well as hand laid cloths. When we want to control weight and thickness on say and animated part we will hand lay and then compact under vacuum. For a static part where the either the thickness or the weight is not so critical we will use chopped roving for layup and compact with rollers and stippling brushes.

Hope this helps, back to you Grant,

Sam

[popeye the sailor]

she's look'in super Grant.......I've done very little with resin.   great to see someone shed light on the process  

[aydingocer]

Very very smooth coating. I wish I could have done the same for my Aquarama.

[gjdale]

Thanks again for all the encouraging comments and "likes". Progress seems to have been slow, but that's because I've spent a lot of time waiting for resin and/or paint to dry!.  A minor update tonight:

 

After a third coat of resin, the hull was wet-sanded with 120, 240 and 360 grit sandpaper and is now ready for finish coats. That left me with something of a chicken and egg dilemma. Should I apply the colour to the bottom of the hull before commencing clear coating, or should I clear coat the top/sides to a finished state before applying the bottom colour? I’ve seen it done both ways, so I figured it didn’t make a critical difference in the end.

 

I decided that my approach would be:

1. Apply bottom colour
2. Apply one clear coat over everything (mainly to protect the bottom colour from lifting with the masking for the next stage)
3. Apply waterline boot-topping stripe
4. Apply graphics
5. Apply remainder of clear coats (to a total of five coats)

 

I decided on a copper bottom colour as this is fairly typical for these boats. I marked the waterline as indicated in the plans and then used Tamiya masking tape to define the “wet edge”. Regular painters tape and some scrap paper completed the masking job and I was away.  I started with two coats of white automotive primer, with a very light sand afterwards, and then applied three coats of  Krylon “Premium Copper Brilliance” from a rattle can (as per my earlier trials), with a light wet sanding with 360 grit after the first coat and 600 grit after the second coat.

 

I decided that I was happy with the result and unmasked her this evening. There is a little bit of fairing required to remove the raised edge along the ‘wet edge”, but otherwise it looks okay – certainly a big improvement on the white plastic!

 

 

The photo shows the sanded resin with a whitish appearance. This will disappear with the application of the clear coat.  Here’s a couple more shots to show overall progress.

 

 

 

Next I will apply a coat of clear over the entire boat before re-masking for the boot-topping. This painting lark is a slow process….

[rafine]

Grant, I know nothing at all about fibreglassing a hull, but I can certainly see that you have thoroughly researched and thought the process through. The preparation shows in the work you've done.

 

Bob

[Keith_W]

Looking at the pattern of your sanded finish, I can see that managed to knock down most of the imperfections of the first few gloss coats. I could see quite a lot of orange peeling in your earlier photos. I just wanted to shout out some encouragement, don't let your patience give out just yet. Work at it and make it super smooth! 

[dgbot]

Have patience and give it a good shop.  I found a photo that might inspire you a lttle.

David B

 

 

[cog]

Stunning job, Grant. I like that copper(ed) bottom ... nearly a period time ship (of the line)

Edited November 13, 2016 by cog

[gjdale]

Thanks Bob, Keith, Carl and David for the comments (and the pictures David - very cool), and also for all the "likes".

 

I applied one coat of clear coat this week in preparation for the boot topping and artwork. I used my new mini-spray gun for this and learned a little in the process – primarily that my little airbrush compressor is only just up to the job for this. The spray gun sucks a lot of air (it needs about 30 - 40psi to shoot the clear coat), so short bursts and some patience while the compressor re-charges are required. There is a little bit of an ‘orange peel’ effect evident on this coat, but that will disappear with further coats and light sanding (and improved operator technique).

 

To apply the boot topping, I used two new products. First up, some pinstriping stencil tape from Finesse. Quite expensive, but does a super job. Essentially it is two pieces of masking tape with a clear carrier tape over the top. It is applied as “one” tape, and then the carrier tape is removed, leaving two perfectly parallel masking lines.

 

 

The second product I stumbled across in the LHS while picking up some extra paint. It is a masking tape combined with plastic sheeting. It comes in a roll like this”

 

 

As you can see, one edge has standard Tamiya yellow masking tape, which is pre-attached on one edge to some thin plastic sheeting that unfolds to be 550mm (nearly 2 ft) wide. By running the tape along the outer edge of one side of the Finesse stencil, the sheet was wide enough to go completely over the model where it was taped down with some more Tamiya tape to the stencil on the other side. The process was repeated for the opposite side of the stencil and in no time at all the hull was completely masked except for the boot topping space. If anyone is interested, the Tamiya product ID is 87164**640

 

The boot topping was airbrushed on using Vallejo Model Air White (71.001) at about 15psi. The first coat was left for about two hours (I had to go out) and then a second coat applied. About 30 minutes later I removed the masking and voila!

 

 

 

 

I’ll leave this to fully cure overnight and then apply another clear coat before starting on the artwork.

Edited November 18, 2016 by gjdale

[hof00]

Looking Awesome!!

Been following the "Chris Craft" Builds. What did you use for the "Shiny" stuff? (I have a vested interest, sorry, but good to ask.)

Don't really want to use Lacquer on the Pen Duick, it ended in tears last time..

Got some "Testors" Lacquer but reticent to use this also, Finally,  purchased some Vallejo Gloss Varnish. (Water Based)

Have done a Test piece using the Vallejo stuff and looks o.k. over acrylic.

 

Don't want to "Hi-Jack" your awesome thread, maybe a PM? Too Late?

 

Cheers....HOF.

[gjdale]

Thanks Hoff - no problem answering questions here - that doesn't count as a "highjack".

 

It started with fibreglass cloth and 3 coats of West Systems Epoxy Resin (using their 207 Hardener). The "shiny" stuff that goes over that is a Feast Watson Spar Marine Varnish that has been diluted with 10% Mineral Turpentine and sprayed on. At the moment there is only one coat of that in place and it looks almost satin in appearance. By the time I have applied the remaining 4 or 5 coats, it will look a lot shinier. Then the hard work of polishing will begin. I have a cunning plan for that but you'll have to stay tuned to find out what that is........

 

Incidentally, the main reason for using the Spar Marine varnish is that it contains UV protection. As this boat is going to be exposed to the elements, it makes sense to use products designed for such.

[hof00]

Thank you Sir.

Following you build with interest. (The other Chris Craft also.)

 

Happy that I have not compromised your Build Thread!!

 

As stated before looks awesome!!

 

Don't think that Turps" would be good for my Build

 

I salute your efforts thus far.

(Am toying with the idea of the A/L Marina II as an R/C Project, Thus far, all mine are static, no shame in that though.)

 

Cheers.... HOF (Harry)

[Keith_W]

Now that is just stunning. One little thing though - there is a tiny bit of orange peeling on your finish. When I was still making model cars, I used extremely fine grit sandpaper to get rid of it. Might I suggest you try this: https://www.thesandpaperman.com.au/micro-mesh-reg-1500-regular-sheet-150-x-300-mm.html

 

As you can see, grits of 3200, 4000, 6000, 8000, and 12000 are available. This will give you the flawless finish that your model deserves.