boat stuck in mould

Hi Whacker,
The gun looks pretty familiar, but then they're almost all alike. Once you get the gun cleaned up see if you can find any markings that might be the orfice diameter...like 1.2, 1.4, or 1.8. At first glance though I would say it'll be fine for spraying PVA. Shop around and see if you can find a small pressure gauge/ regulator that you can screw right onto the gun...it'll give you a better idea of the actual pressure at the gun while you're spraying and a finer control setting then the regulator on the compressor. You can shoot PVA without one...it's just nice to have.

For small projects I don't mind using a brush to apply gelcoat because it saves me clean-up time and acetone, or if the weather doesn't allow me to take the part outside to spray. But for the most part I prefer the uniform coverage I get inside the mold when spraying because it's makes my skin coat easier to apply. Brushing also means your gelcoat application is noticeably slower then spraying which can lead to all sorts of problems. Also things like brush strokes in the gelcoat showing through, thick and or thin spots, having to use two or more coats to get the coverage you want, or simply having it flash off in the pot before you're done all add to the long list of "things I've done wrong".

I've tried to learn from my mistakes, so today I use a really simple, cheap and easy to clean drywall texture gun for shooting my gelcoat. They come with nozzles big enough to shoot anything you want, and only have two moving parts. I added an air shut-off valve at the gun, a different cup, and tapered the rod tip to give me a better spray pattern.

Personally, I prefer spraying gelcoat in most instances simply because I get a more uniform layer over the entire mold surface. The high spots have just as much gelcoat on them as the low ones. I don't end up with puddles in places like the keel, I don't have to get up close and personal with every square inch of the mold, and I don't disturb any release agent that I've applied to the mold.

Don't get me wrong you can screw-up gelcoat spraying too...Tunnels has the pics to prove it...I just screw up less often spraying then I do brushing.

MM

 

well what can i say !! hand brushing is a excise in technique and how to master the use of the humble every day buy any where type paint brush . biggest thing is getting thickness and a even thickness all over!!, Brush strokes and thin spots are just the way you hold our tongue when you are brushing !!. dip into the gel pot get a good amount on the brush !!,then brush and apply to the moulds surface and the last stroke brush back into the part you already covered but very lightly and lift off without stopping anywhere !!, the same with the next brush load and finish by brushing back into and over what you already done very lightly holding the brush between 2 fingers if need be and lift off without stopping . this gets rid of the brush strokes and the light brushing will leave a decent thickness of gel behind !! also lay the brush back on a 60 degree angle and trail the brisles !!,the more vertical you hold the brush the less gel gets left behind !!, never use a brush with short brisels they should always be long .

Another good tip i always use on smaller itams is when you lay that first skin of glass ,pigment your resin with some of the same coloured gel coat!!, it gives the gelcoat deepth and even if it gets scratched at some time its far less noticeable as it hasnt got into the colourless resin behind and shows as being a dark colour .

Spraying is an art as i always say and if you dont get it right and get thick places they can be brushed to spread the gell out and not get pre-release and pulls specialy in deep corners and where 3 surfaces come together in one place . again its all in the techneque and the flick of the wrist . internal round things are amusing to watch guys spray and how they go about it . inside boxes is another and everytime theres that shot and blast in the face of gel spray and air happens everytime !.
knowing how much thickness you got is an art and have to take notice of the sprayed texture pattern on the surface . if it differant some where its possibly thinner . gel coat does not flow out like paint and its why painters have difficulty with spraying gelcoat , using a high pressure venus gelcoater is fun to watch guys using it !!, they pour on a lot of product yet its smoother than a gun spray . next thing is drifts and runs and whole areas start to move just like a snow drift . once gel starts to move down the side of a mould its hard to make it stop .always carry a rag and a thickness gauge with you at all times !! even experts get it wrong sometimes !!. temprature at the time and light have a great influance on getting it near perfect . cant see properly so spray will be heavy!!, temprature up the gel is more viscos and will slide easyer as the thixo isnt able to hold it in place because it more liquid .
Dont ya just love it all !!. i think i will go for a walk and smell the flowers !!.

 

Wacker82, You obviously are not married mate cos if you were your wife would have been able to tell you all you needed to know about how to remove a stuck boat from a mould....I remember well my one telling me all about it....such is life.

 

progress ?? any progress ??

well should be all sanded and ploished and 4 coats of wax and into making boats !! yes or no ??
where are you at ??
no news is nor good news !!:?::idea:

 

not happy with the supplier, ordered the material sat only coming today. so all ive done is feathered the edges of the missing parts of the mold.
ill be putting the first layer of gel coat on once i get it, pictures will follow today. i promise.

 

If you have any gel coat at all reguardless of colour you can fill some or even all and sand it . if you live on a desert island you use any and all things to fill with but the job gets done no matter what .if you have a friend thats a car painter get some bondo and hardener from him and fill the waste places and sand it just below and top the last with gel coat !!can even add a little resin to the gel to make it flow out smoother . what ever you use after a month or so you have to lightly sanded repolished and waxed as it will begin to show a slight mark in the finished product !! .
anyway have a good weekend !!

 

he wont be long now, any minute. ill bulling to start it

 

material has landed, delighted



the damage to be fixed, all feathered and ready for flow coat.







first layer of flow coat gone in

 

PVA Coverage

Whacker,

Did you spray apply the PVA? Are you absolutely sure that you have PVA everywhere including the vertical surfaces of the keel sides and rub strips at the bottom of the mold?

It is so important that you have. 100% PVA coverage. If you don't the boat will likely get stuck again.


best of luck


Allan

 

ive rang the suppliers and asked them about pva, they asked me will i be puttiing on mold release wax aswell,when i said yes they strongly recommended me to either put pva on or wax one or the other, because there is traces of silicone in the wax and the pva will react to cause a chemical reaction. he said that they have experimented by doing this and said that they found that it smeared and transferred onto the product, he was saying to try it on a piece of perspex if i would like to see for myself but he strongly said not to do this, as the mold release wax has all the additives it needs to cancel out using the pva. so what do ye think.

 

mold is under repair, no wax or pva has been added

 

silcone in Wax?

Whacker,

I am not familiar with the products shown in your posted photos. I have never heard about compatibility issues between mold wax and pva, but i have no reason to contradict your supplier.

I do believe that the most common may to ensure a good release it to have a totally perfectly prepared mold and then wax it w/ 5 to 6 coats and then apply the pva. There are loads of people here with more experience I have and I would suggest waiting for their input re: leaving out the pva before proceeding.

I have been infusing canoes since 1999, with only about 25 boats built. Most of my knowledge has been gained by trial and error, until I came across this site.
I have made probably every mistake that is possible along the way.

To refinish a mold, I wet sand it thru all grits down to and including 2000.
I then polish the mold with two grades of mold polish and then wax it 5 times.

When the mold is ready it is totally smooth and so shiny that it actually looks wet.

I have applied pva via spray and by hand with a smooth sponge.

My canoes have such a fine forefoots that I found it difficult to get 100% coverage with spraying. After lots of messing around with different methods, I now simply pour about 2-3 oz of pva into the mold and spread it around with a smooth sponge. As the alcohol quickly evaporates you can see and feel the pva building up a nice smooth coat. I can pva the entire mold in about 10 - 15 minutes. Using this method automatically ensures that you have 100% coverage and has absolutely no orange peel. The only clean up I have is to put the sponge back in its zip lock plastic bag, so that it is clean and ready for the next boat.

I hope this helps.

Allan

http://www.fibreglast.com/product/S...h_1102/Supplies_Tools_Polishing_Sanding_Tools

 

got started on the sanding today, started with 220grit moved on to 400, 800, and 1200grit really happy the way its coming out, extremenly smooth with no high spots or low. its long and tedious work, but the reward is enough to keep me going. pictures to follow tomorrow

 

Whacker,

As you change grits it is very helpful to rinse the mold and change out the water in your bucket, if you are using one. This will help eliminate loose grit from the previous grit and save you time.

I also find it helpful to use a small rubber squeegee (1" x 2") to immediately dry spots as you progress. They are generally available at any Auto parts store for 2 -3 dollars. It will enable you to better see your progress.


Good luck and have a good time.

Allan

 

thanks variverrunner, constantly spraying more water on at the minute it starts to turn into putty, changing the cloth to keep it clean. wax on wax off business!