What's new

Another Nova from across the pond saying Hi!

islandman

Member
Well the buck is waxed and the cutout areas have had aluminum tape put over them to reduce the rough surface and make it easier to pull from the mold. I will start the flanges for the mold tomorrow and then maybe PVA the next day. This should allow the paint time to harden before I start putting hot gel coat and matt down on it.



I’m also testing some tapes on the non visible surface of the buck to see which does the least damage to the paint surface. The aluminum stuff will be used to hold the flange but I was advised by another member who does lots of this stuff that the aluminum tape can mark the painted finish

 

islandman

Member
I started to put the flange down for the first part of what will probably be a 6 piece multi-part mold. Rather frustratingly I ran out of aluminum tape with only a small section left to complete it. The shop was closed so I will have to continue tomorrow. I was able to at least seal the flange joints with candle wax for the part that I did finish.



Another frustration is that the fiberglass / filler has already started to move. When I picked it up from paint it was perfect, now I can already see some of the joins that are appearing as the filler sinks and fiberglass moves. One of the annoying things with fiberglass is that in heat it still moves about even after its cured :mad:
 

Brett Proctor

Well-known member
Another frustration is that the fiberglass / filler has already started to move. When I picked it up from paint it was perfect, now I can already see some of the joins that are appearing as the filler sinks and fiberglass moves. One of the annoying things with fiberglass is that in heat it still moves about even after its cured :mad:

Use to have this problem also.

I was curious why this was happening because you can buy blocks of the same foam and it didn't do this.
Well after reading the instructions on the cans of the foam it said allow min 24 hours to cure(depends on air temperature). I was starting to cut and form it after about an hour that it was poured.

Letting it cure for 24 hours helped alot but I still got small pockets that showed signs of the foam reacting with the filler.

I'm using casting resin now to seal the foam, I apply that(by brush), then sand it smooth. If I break through to the foam during sanding it I'll apply another coat of the casting resin over the foam that is exposed and it gets another sanding. if needed I use a finishing putty to fill in the imperfections.

If no sanding is required after the casting resin is applied the finish of the resin is a smooth glossy finish.

Another thing about the resin is it cures fast. Starts to setup in about a minute. There maybe other brands that cure slower but I like the fact that it cured fast. Just don't mix more than you can brush on within the time limit.

Resin viscosity starts out thin so it flows into the air pockets of the foam easily then as it cures it starts to thicken. Once it got to the consistency of syrup I stop applying it and let it continue to cure

Cures a little different than laminating resin. It doesn't gel up like laminating resin but just continues to get thicker till it is fully cured.

So far I've had good results with it not reacting with the foam.

Sorry I didn't get this info to you sooner.

I see you like that aluminum tape*laugh* Works great for me also
 

islandman

Member
Well after reading the instructions on the cans of the foam it said allow min 24 hours to cure(depends on air temperature). I was starting to cut and form it after about an hour that it was poured.

Ah...that's exactly what I do! I normally start shaping and cutting within an hour or two of pouring :(

Too late for this piece now as I'm definitely not redoing it...The fact I will be covering the part in Alcantara cloth eventually is my only consolation *nothing to see*
 

islandman

Member
I was asked this question on the Euro-Nova site and thought I would pose the same question here to see what others think who make molds far more than I do


From Euro-Nova : "To PVA or not to PVA its a question I am asking myself, do you think you need it? its good if you are doing something with FG and just want to pull it off a mould, like your air vents, but making a mould from a plug it wont have such a good finish using PVA?"

So I guess it comes down to does and will the PVA change the finish of your part if making a new mold. My initial thoughts are yes it probably will, and more so if the PVA is brushed on rather than sprayed on. So should I consider only waxing when I'm making the mold for me new dash??

Ideas, thoughts, recommendations anyone -confused*
 

ratrog64

Well-known member
I have been taught always use pva untill the mold is well seasoned.

If your plug is perfect and soomth and shiney and is NOT PAINT but duratek or a similar catalyzed polyester based product, maybe take a chance, maybe. I wouldnt!

Without the PVA you stand a good chance of sticking your mold to your plug.
 

Peter

Active member
I have been taught always use pva untill the mold is well seasoned.

If your plug is perfect and soomth and shiney and is NOT PAINT but duratek or a similar catalyzed polyester based product, maybe take a chance, maybe. I wouldnt!

Without the PVA you stand a good chance of sticking your mold to your plug.


That's how I f****d up my mould. *whaah*
 

Brett Proctor

Well-known member
Comments are from experience.

In my early years of fiberglassing I was told by an owner of a fiberglassing company here in town that once you apply a good layer of wax down on the mold you can get away with out waxing for a few times but don't omit the PVA process.

Well a while back I didn't have any PVA and I thought I could get away with out using it since it was just a small part so I put down about 4 layers of wax and fiberglassed the part. In the end, the part would not come out of the mold and I ended up destroying both the mold and the part while trying to get the part out.

I've tried different brands of PVA and the finish they give were all different but they all did their job.

I've brushed on PVA but always had issues of getting rid of the brush strokes in the finish.

I've wipped it on with a paper towel and have been able to get half way decent results. Just make sure the paper towel is a high quality and wont come apart as you wipe on the PVA.

Spraying it on has gotten me the best results on the final finish and depending on what brand you use some PVA will give you a nice high gloss finish more than others.

But what if you have a small part and don't want to get your spray gun out and then have to clean it? OK some times I get lazy, I admit it

I've tried hand pump spray bottles for that occasion with good results.
Because the PVA has a thicker viscosity than water the spray bottle wont atomize PVA as well as water, so what I do is get the finest setting that the spray bottle will spray the PVA and spray it on, then with a paper towel wipe it around the mold. I do this a few times till I know all the mold is covered evenly with the PVA. The I'll dilute the PVA with water enough that the spray bottle will spray the mixture in a fine spray. This is done to give the final top surface a smooth finish but just a light application otherwise you could cause the PVA to "run"
If the final finish isn't to your liking give the PVA plenty of time to dry and apply another light misting.
I have tried to use the diluted mixture by itself and it has worked with no issues but you must make sure you got everything coated with it because the resulting film covering the part will be alot thinner and that will leave no chance for error

There have been times when I've applied more than enough PVA but the finish wasn't to my liking which in that case straight water in the spray bottle with the setting as fine as the bottle can spray and a very light misting will sometimes bring out a nice high gloss finish to the PVA

Of course not all spray bottles are created equal so finding a good one may take some time.

Some spray a nice fine mist at first but then it spits out a big drop and messes everything up.

When I say a mist I mean a mist(something like a fog). I'll spray a mist over the top of the part(not aiming at the part but spraying over the part)and the solution lightly settles down over the part.
 

islandman

Member
Comments are from experience.

In my early years of fiberglassing I was told by an owner of a fiberglassing company here in town that once you apply a good layer of wax down on the mold you can get away with out waxing for a few times but don't omit the PVA process.

Well a while back I didn't have any PVA and I thought I could get away with out using it since it was just a small part so I put down about 4 layers of wax and fiberglassed the part. In the end, the part would not come out of the mold and I ended up destroying both the mold and the part while trying to get the part out.

I've tried different brands of PVA and the finish they give were all different but they all did their job.

I've brushed on PVA but always had issues of getting rid of the brush strokes in the finish.

I've wipped it on with a paper towel and have been able to get half way decent results. Just make sure the paper towel is a high quality and wont come apart as you wipe on the PVA.

Spraying it on has gotten me the best results on the final finish and depending on what brand you use some PVA will give you a nice high gloss finish more than others.

But what if you have a small part and don't want to get your spray gun out and then have to clean it? OK some times I get lazy, I admit it

I've tried hand pump spray bottles for that occasion with good results.
Because the PVA has a thicker viscosity than water the spray bottle wont atomize PVA as well as water, so what I do is get the finest setting that the spray bottle will spray the PVA and spray it on, then with a paper towel wipe it around the mold. I do this a few times till I know all the mold is covered evenly with the PVA. The I'll dilute the PVA with water enough that the spray bottle will spray the mixture in a fine spray. This is done to give the final top surface a smooth finish but just a light application otherwise you could cause the PVA to "run"
If the final finish isn't to your liking give the PVA plenty of time to dry and apply another light misting.
I have tried to use the diluted mixture by itself and it has worked with no issues but you must make sure you got everything coated with it because the resulting film covering the part will be alot thinner and that will leave no chance for error

There have been times when I've applied more than enough PVA but the finish wasn't to my liking which in that case straight water in the spray bottle with the setting as fine as the bottle can spray and a very light misting will sometimes bring out a nice high gloss finish to the PVA

Of course not all spray bottles are created equal so finding a good one may take some time.

Some spray a nice fine mist at first but then it spits out a big drop and messes everything up.

When I say a mist I mean a mist(something like a fog). I'll spray a mist over the top of the part(not aiming at the part but spraying over the part)and the solution lightly settles down over the part.


I like the spray bottle idea, especially as I don't have spray equipment here. I will see what I can find and give it a try.

Thanks Brett and Roger for your input and ideas, much appreciated *thumbs up*
 

islandman

Member
I found some time eventually to do some more on my mold, I did screw up the big top section though, I left the PVA on a long time (about 3 weeks) before doing the gel coat as I had to deal with my wife and the accident. It was only when I was applying the last of the gel coat to the depression for the wiper motor I realized that the PVA had shrunk and pulled away from the part in the corners. As I had painted on 95% of the Gel coat at that stage and it was going to set soon I just had to make do and puncture the PVA skin and try to cut the piece out that pulled away and put as much gel coat as I could in the area. I know when the mold is pulled I will have some filling to do in that area. Another issue I noticed as laying the fiberglass down was that the paint shop must have done some sanding on the back edge of the wiper depression also as it was slightly undercut (it wasn’t previously). So all in all I’m going to have fun trying to pull the mold off the part, I hope I just don’t destroy it in the process!





The back and sides went OK, but then they are largely flat sections. The other area I struggled with was the front as it was full of right angles and narrow sections, so trying to get the fiberglass to conform and not lift creating air bubbles which was a real challenge. Its very far from my best work, and I found that leaving long periods of time between each section means I got out of practice as well as forgetting to apply the various lessons I had learnt, like not trying to do too much in one go.







So I will have to wait a couple of days then start pulling the mold and see what state it is in, or if it will pull at all.
 

islandman

Member
Glad to see you back at it Phil!

I hope the wife is doing well and seeing improvements daily!

Its David btw ;)

and yes there are daily improvements with the wife, albeit the nagging has started with them also :(

In about 9 weeks she should be able to start to try and walk again, then hopefully I can spend less time as a carer and more time on car bits...... however my annual pilgrimage to the UK in May for the biggest kit car show in Europe has been cancelled due to my duties here which I'm pretty unhappy about as there should be a good line up of freshly restored Nova's there this year *thumbs up*
 

ratrog64

Well-known member
Its David btw ;)

and yes there are daily improvements with the wife, albeit the nagging has started with them also :(

In about 9 weeks she should be able to start to try and walk again, then hopefully I can spend less time as a carer and more time on car bits...... however my annual pilgrimage to the UK in May for the biggest kit car show in Europe has been cancelled due to my duties here which I'm pretty unhappy about as there should be a good line up of freshly restored Nova's there this year *thumbs up*

I know its David, I don't know where the Phil came from. *insane*

I'm glad to hear she is doing well, the nagging is just a reward for your service!

I always check in on the Nova site and there are a few cars I'd like to see for my self in person. There is always next year ..... hopefully .......
 

islandman

Member
Well I couldn’t resist the temptation to pull the mold, I figured most of the parts had been done a long time ago with only the last piece being a couple of days old.



The sides and back popped off relatively easily, and surprisingly so did the top which surprised me. It turns out the area where the PVA pulled away wasn’t nearly as bad as I feared. I guess I filled enough gel coat and resin in to fill most of the void. It will still need some filling though.



The front sections however fought me every step of the way to get the mold off. The dash buck didn’t survive that well and bits that were basically fibreglass filler and bondo split in the process. One lesson I learnt was to make sure you cut back the mold right to the part, or even further shortening the part as these are the areas which clung on for dear life!

I have a few areas where air bubbles that were behind the gel coat caused the gel coat to break leaving voids, not too many though all though some bits are hard to get to in the narrow recesses.



So I have a question, how best to fill these areas and what to fill them with? Gel coat and sand it back? For some of them I was thinking of just using candle wax as this is probably a one time mold? Thoughts or ideas anyone?

Overall I pretty happy with the mold and the learning process, its far from perfect but could also have been a lot worse.

 

islandman

Member
So I have a question, how best to fill these areas and what to fill them with? Gel coat and sand it back? For some of them I was thinking of just using candle wax as this is probably a one time mold? Thoughts or ideas anyone -confused*


Another question, do you guys always put tissue down as your first layer on the gel coat? If so is this to make it easier to confirm to tighter angles and ensure no air voids before laying the thicker glass fibre. I had thought about trying this but wasn't sure doing it on my newly made mold was the best time to experiment. but having said that I do have some narrow deep recesses that may benefit from this approach if it works?

Brett and Roger, what do you guys think about my two question?
 

ratrog64

Well-known member
If i have small repairs I do use gelcoat to fill them it. A little tip is after you fill the hole with gelcoat put a small piece of masking tape over it to seal it so it will cure and not be sticky. You can also use gelcoat that has wax in it to self seal. Some imperfections I do just use clay to fill the void especially if the part will get a little massage prior to prime and paint.

As far as laying up your part. I always use mat as my skin coat or chop from the gun. Cloth tends to print through the gelcoat. I'm not sure what you mean by tissue. For the tight areas you can tear the mat as big or small as you need to fit anywhere.
 
Last edited:

islandman

Member
I'm not sure what you mean by tissue.

Fibreglass Surface Tissue looks just like normal tissue that you blow your nose on, you can't see any pattern or weave and its about as thick as a normal tissue, so bends to tight angles better that 1 1/2 oz matt
 
Last edited:

Brett Proctor

Well-known member
So I have a question, how best to fill these areas and what to fill them with? Gel coat and sand it back? For some of them I was thinking of just using candle wax as this is probably a one time mold? Thoughts or ideas anyone -confused*


Another question, do you guys always put tissue down as your first layer on the gel coat? If so is this to make it easier to confirm to tighter angles and ensure no air voids before laying the thicker glass fibre. I had thought about trying this but wasn't sure doing it on my newly made mold was the best time to experiment. but having said that I do have some narrow deep recesses that may benefit from this approach if it works?

Brett and Roger, what do you guys think about my two question?



Since this is a one time thing and durability is not an issue if candle wax will work then use that. There are other ways to fix the problems but the candle wax would be the easiest and cheapest, I've used mold release wax to fill in small voids also.

I've heard a few stories about the use of tissue or as it's called here deck cloth.

First is that its put down on the gel coat so the next layers of glass don't bleed through, and the second story is its used if gel coat is omitted.

To fill in areas that you can't lay the glass in I've used a mixture of glass beads and resin and mix that into a paste that or mix up some glass fibers and pack that in. I then fill the area in to a point where laying the glass will conform to the curves.

Also if your having trouble getting the glass mat to lay flat on tight curves, pealing it apart to get a thinner section of glass works. Of course buying a lighter fiberglass works also. Once its built up to a point where you can lay a heavier glass over it you can start with that.

I'm assuming during all this glass work your using laminating resin and not finishing resin.

The difference is finishing resin has wax in it and laminating resin doesn't.

Use only laminating resin or you risk the chance of the layers of glass coming apart.

The wax acts as a sealer. If you where to use a finishing resin while your where laying up the glass you would have to sand the glass between layers to remove the wax.

If I forgot something let me know
 

islandman

Member
To fill in areas that you can't lay the glass in I've used a mixture of glass beads and resin and mix that into a paste that or mix up some glass fibers and pack that in.

I did think about using fibrelgass filler to achieve a similar effect as mixing beads and glass fibres



I'm assuming during all this glass work your using laminating resin and not finishing resin.


Actually until I saw a similar comment on the Euro Nova site I didn't know what the difference was, but you explained it well. I have been using General Purpose Polyester Resin (no idea if it has wax, will talk to the supplier when I go to buy more) and have had no issues so far with separation. I did just google to read about the differences and read in one place that if you are doing several layers the heat generated allows the resin to cure regardless of the wax content. So maybe that's how I have been getting away with it so far
 
Top