Jump to content
This site uses cookies! Learn More

This site uses cookies!

You can find a list of those cookies here: mysite.com/cookies

By continuing to use this site, you agree to allow us to store cookies on your computer. :)

Merlin

Members
  • Content count

    175
  • Joined

  • Last visited

Community Reputation

13 Good

About Merlin

  • Rank
    New Member

Contact Methods

  • ICQ
    0

Recent Profile Visitors

1,432 profile views
  1. any chance we can see the photos ? Merlin any chance we can see the photos ? Merlin
  2. Thinning Halfords paint?

    Vontrips, So did it work ? Merlin
  3. Cellulose thinners it is then. Thank you (a belated one !) Do you modellers also decant and thin the Halfords white primer and again is that with cellulose ? Same situation otherwise of clouds of spray in a small modelling studio and overkill especially if trying to prime intricate parts. I have some Hycote white primer, is that also suited to cellulose ? I like the Mr Surfacer primer but its grey not white so for red or a white topcoat for example I would prefer white. Merlin
  4. Hi Panzer948, Just revisiting this thread for inspiration as I have found my Signifer oil cart, and all the images are afflicted by photobucket's move to ask for money, and so wreck the internet which has become the reference for life, any chance you could use a free host and repost them ? Everywhere I am going images vital to our hobby have vanished. terrible state of affairs. Merlin
  5. Hi, For most castings simply mix up the resin then pour in. Fast Cast doesnt need de-bubbling. Lesson learnt :-) Q1. If an object is such that as the resin is poured in, it traps air into part of its shape, and that shape cannot be air vented with a channel etc, what resin should one use for this ? Q2. Also what vacuum achieved time on the chamber should be aimed for ? My pump 42.5L/M, ( all I can afford brand new...as the next pump price that does vacuum on 26L in 30 secs is £800 ), having added more solids to the 26L chamber, so its now in theory 10L of air space, sees the following stages reached on the gauge:- 27 1:23 28 1:36 29 1:57 29.5 2:13 29.7 2:27 30 2:42 30.3 3:10 30.4 3:25 30.5 3:44 and no go beyond 30.5 Q3. is it in fact possible to bulk out the 26L chamber to achieve 30 sec vacuum reached time with a 42.5L/M pump ? Q4. at what stage is this going to be degassing and when should I let air in ? The one fast cast I have has pot life 2 to 3 mins. Another I have is supposed to be 6 mins. That set with big bubbles in 5m:16sec By the time I have added in part B then stirred it, then pipetted it into mould, placed lid on and switched on pump, I am at setting time it seems before vacuum has had chance to do its thing.. Pipetting Part B to get 7.0 g of B into A, sees three squirts and a careful 4th where drip by drip I achieve the same weight, allowed 1% variance at most, one drip too many can break the rule. Here is a timed session on Fast Cast polyurethane resin pot life 2 to 3 mins, with 10% black pigment added to A :- 00:00 as part B first hits part A. 1:35 end of stir of 30 secs duration, 18mm wide stirring stick for greater effect, any wilder and it flicks out of beaker at me ! 3:35 all is now into film canister (Pipette is slow method of getting mix into mould, need to rethink that ! ) Lid on, flip handles, start vacuum pump. 10 4:22 15 4:31 20 4:47 22.5 5:00 25 5:12 27 5:31 appears to have slowed, let air in, result, 4mm at base of canister is solid, the rest , totalling 20m height is a resin bubble mix ! and its hot to touch ! 6 minute one no better, having also added 10% black pigment, in fact it had a whitish substance in small areas across the moon cratered bubbled surface, and was dark grey at best. Q5. What was that white stuff, it can be poked away with cocktail stick, but doesnt just wash off. Incompatability of black pigment or side efect of 'boiling' ? Q6. The longer I leave it in there the bigger the bubbles get. One will never get to no bubbles it seems, so if one needs to get air out from a shape , is a 30 sec vac chamber pump at £800 going to be the answer or will this stuff 'boil' and bubble ? Q7. Does resin get hot under vacuum and forever generate bubbles, as these bubbles get bigger and BIGGER...as time passes ! Merlin
  6. Hi, Cheers. I will try and get some. I just tried Tamiya white putty but it took 8 or so hours to dry hard., as did Mr Surfacer 500. Merlin
  7. Mr Hobby Primer Surfacer is suggested now for Resin, but at £20 for one can in the tnt dpd etc delivery system because Royal Mail have gone silly mode, its a no go. Will have to be Halfords and save £15. Halfords Plastic primer or standard primer for resin, does it make any difference ? Is the plastic primer better suited to resins ? Merlin
  8. Hi, Trying to get Mr Hobby rattle cans, royal mail wont deliver, and courier is same price as can so £20 for one can of primer. Nuts Anyone found a shop selling Mr Hobby without crazy delivery fees ? Merlin
  9. W&N Galleria varnish possible issue?

    Do some test pieces, same varnish and flow improver mix but over a variety of subjects, see if its the varnish gone off. Try VMA again but a different colour, also just Valejo Model colour, of the same colour if you have it, see if its the thinner Valejo add to it that is the cause. ditto with less of the flow improver, and none of it, is it the flow improver ? establish the cause. resolving it, warm airing cupboard, minimal humidity maybe. I have same but with satin humbrol varnish well stirred over new matt humbrol paint, 3 weeks and still tacky. Merlin
  10. Which wash is best over enamels ?

    Hi, I have Johnsons Klear floor shine, is that same as future floor care, its what we use on gloss coating models, though now a collectors item seeling for big money. Merlin
  11. Which wash is best over enamels ?

    Hi, Normally I gloss coat with acrylic, let dry thoroughly then mix up an oil paint from tube (W&N or Abteilung) with odourless thinners. Mixed results by the way, sometimes the faded effect of the meniscus vanishes leaving just black pigment in the crease of the item, sometimes even that sems to shrink to give gaps in it. However this time I have an enamel painted item with its various details and need to get a wash to run into the details gulleys, acrylic varnishing the item is not an option as its big with items glued on now, and would mean a load more work and anyway I have it in the surface finish I desire already., including buffed metallics, I am not masking off the parts all over again ! Which wash would give best results, flow well, give graduated edges to the dried wash, etc. What additives should it have, if any ? Merlin
  12. Hi, Resin has oils inherent in the stuff, which will leach through paint, so I hear, so even if given a good scrub with fairy liquid then sprayed with e.g. Halfords grey primer, in time it will show, it is said. Has anyone experience of this ? Resin primers are few and far between, so is there really a need for a dedicated resin primer ? Mr Hobby do one in a jar and one in an aerosol. I see a thread on someone struggling to thin and spray the jar version. No other paint manufacturer has ever bothered with making a resin primer, as far as I know, model shops dont stock such, even the automotive shops sell resin and gauze but no resin primer ....your thoughts please. What is best way to primer resin to receive Hycote 'double acrylic concentrated' rattle can paint, then cellulose on top of that, for a car. Merlin
  13. Hi, brand new unopened part A and B containers. (well , had them 1 yr but unopened stored in cool place), told makes no difference might increase working time a little. exposure to moisture was the time it took to undo the top for the first time and pipette out the liquids, a couple of mins. Stirred it fast as time was ticking and lost time to the measuring out., but surely degass would see those come out. No pouring done at all, as degassed it in the mixing vessel. Having bought this pump/chamber combination and liquids by explaining what I hoped to be casting, if this is 1/4 of the power it needs to be, then thats a total waste of my money, mis-sold etc etc...I cant go buying though a pressure chamber and pressure pump. The mould I have must not be pressed as the scalpel cut side will open out and resin will get out. Squeezing moulds ???..surely that would encourage resin seepage ? I needed a vacuum pump/chamber to degass the silicone but cannot afford pressure system as well. Letting the inrush of air diminish remaining bubbles sounds useful, but it wouldnt have tackled those massive bubbles, 5mm diameter they are. But why did I have massive bubbles forming after 5 mins and beyond, they are down in the resin like swiss cheese. Still not sure why. Imagine if that had been my mould ! Merlin
  14. Hi, Resin casting, I mixed equal parts A and B of a fast cast polyurethane resin using weight. stirred well, placed beaker into chamber, all levers correct, turn pump on, and degass, saw resin rise a bit, small bubbles surface etc, then as chamber reached max air lossage of 24 on gauge, wont go higher, , time now 6mins since mix A to B started, the small bubbles have declined but a few large air bubbles are now appearing, and more, so more degassing to go, then the resin looks less like a liquid liquid, 8 mins elapsed now, so turn off pump, let air in and remove lid, resin has massive airbubbles visible through beaker, like a swiss cheese, as well as part in and out of surface, thin skins over bubbles set as such, frozen in time !!! and its set solid. What use is that ? This beaker could have been my mould as such. Why the larger bubbles in the latter stages , as time goes on, how long did it need to degass if they were still rising after 7 mins or so ? Just what went wrong ? Time wise its impossible to mix A and B by weight and pour into mould then degass so it seems. Timescale:- Best to weigh out equal parts separately then add together, saves some time. start the clock as B poured into A. 00:00 stir well 00:20 elapsed pouring is finished into mould at 00:40 then chamber it and seal is achieved in 1 minute. 24Hg takes 4 mins and 24.4 Hg is 4m51 secs, no progress of needle after that, so thats 4 mins~5mins including mix and pour time. and the resin cures in 4 mins or so. I was told this pump and chamber and resin would be a workable combination, just bulk out chamber with bricks etc for smaller moulds. I am told best it be out of chamber for mould pouring in 2m 30 secs, but it takes 4 mins to get to vacuum, and thats with a 13L chamber (25 bulked out with solids) and an ECVP425 pump. even if one doesnt let it get to 24, there were still bubbles appearing at 6 mins +. big ones by then. Merlin
×